Thin slices of tender potato soak up a punchy Dijon vinaigrette in this fresh mustard potato salad. Instead of relying on a thick, creamy dressing, this version gets its character from olive oil, white wine vinegar, mustard, sumac and coriander, with plenty of dill and parsley added at the end.
The method is simple, but timing makes a real difference. The potatoes are dressed immediately after draining, while they’re still ready to absorb the vinaigrette. Red onion, capers and fresh herbs then add sharp, salty and herbaceous notes without overwhelming the potatoes.
It is especially useful when you want a potato salad that feels lighter and brighter than a mayonnaise-based version.
Here are the main reasons this version works so well.
- The warm potatoes absorb the Dijon vinaigrette instead of leaving the dressing sitting only on the surface.
- White wine vinegar and Dijon mustard give the salad a clean, sharp flavour without mayonnaise.
- Fresh dill and parsley bring freshness to every serving.
- Capers and red onion add contrast to the soft potatoes.
- You can prepare the dressed potatoes ahead and add the herbs, onions and capers closer to serving.
Why The Dijon Vinaigrette Matters
The dressing is the main flavour-building component of this mustard potato salad. It needs enough acidity to brighten the potatoes, enough olive oil to carry the flavours, and enough mustard to tie the mixture together.
Dijon mustard does more than add sharpness. When whisked with the olive oil and white wine vinegar, it helps the vinaigrette come together so the potatoes receive a more even coating.
Sumac adds another tart element alongside the vinegar. Ground coriander and black pepper round out the dressing without turning it into a heavily spiced salad.
Before you start cooking, these are the ingredients that have the biggest effect on the finished dish.
- Small potatoes: Thin slices cook quickly and give the vinaigrette plenty of surface area to coat.
- Dijon mustard: Provides the defining mustard flavour while helping bring the vinaigrette together.
- White wine vinegar: Supplies the acidity that keeps the salad bright rather than heavy.
- Extra virgin olive oil: Forms the base of the vinaigrette and coats the potatoes.
- Fresh dill and parsley: Add freshness after the potatoes have been dressed.
- Capers and red onion: Bring salty, sharp contrast to the tender potatoes.
Thinly Slicing The Potatoes Changes The Salad
This recipe starts by slicing the potatoes thinly rather than cutting them into the larger chunks commonly used for potato salad. That changes both the cooking time and the way the dressing interacts with them.
Thin potato slices expose more surface area to the vinaigrette. Once drained, each slice can receive a light coating of mustard dressing instead of relying on dressing to work its way around larger pieces.
The source method uses a mandoline slicer for this step. The goal is consistency. Potatoes of similar thickness are more likely to become tender at the same time, which is especially important because the simmering time is only about 6 minutes.
Handle the slices gently once they’re cooked. Tender, thin potatoes can break more easily than larger chunks, so the final tossing should be careful rather than vigorous.
Dress The Potatoes While They’Re Warm
The most important moment comes just after draining the potatoes. Instead of leaving them to cool first, transfer them to a large mixing bowl and add the Dijon dressing immediately.
This gives the vinaigrette a chance to coat the warm potato slices before the onions, herbs and capers are introduced. It also means you can mix the dressing into the potatoes while the flavour of the vinaigrette is still the main focus.
Use a gentle tossing motion. You want every slice dressed, but you don’t want the tender potatoes to become mashed or broken apart.
Once the potatoes are coated, add the red onions, parsley, dill and capers. Toss again just enough to distribute them through the salad.
Give The Salad Time Before Serving
This mustard potato salad benefits from a short resting period after everything has been combined. That gives the potatoes time to sit in the Dijon vinaigrette rather than being served immediately after tossing.
You can refrigerate the salad for about 1 hour before serving. If you do, bring it back to room temperature before putting it on the table. This serving approach is part of the supplied method.
The resting period also gives the dressing and potatoes time to settle together, while the dill, parsley, onion and capers become more evenly distributed through the salad.
Mustard Potato Salad Ingredients
This recipe is divided naturally into the potato mixture and the Dijon vinaigrette. Pay particular attention to the thinly sliced potatoes and the dressing, since they determine the texture and dominant flavour.
For the Potato Salad
The potato portion uses a small collection of fresh, punchy ingredients.
- 1 1/2 lb small potatoes such as new potatoes, Yukon gold potatoes, or red potatoes
- Water
- tsp salt
- 1/4 cup chopped red onions
- 1/4 cup fresh chopped parsley
- 1/4 cup chopped dill
- 2 tbsp capers
The source provides the salt measurement as “tsp salt” without a number, so it is preserved here exactly as supplied.
For the Dijon Vinaigrette
The dressing is whisked separately before being added to the cooked potatoes.
- 1/3 cup extra virgin olive oil
- 2 tbsp white wine vinegar
- 2 tsp Dijon mustard
- 1/2 tsp ground sumac
- 1/2 tsp black pepper
- 1/4 tsp ground coriander
These quantities are kept exactly as provided in the recipe source.
How To Make Mustard Potato Salad
The process moves quickly once the potatoes begin cooking, so it helps to have the vinaigrette ingredients and chopped additions ready.
- Prepare the potatoes. Wash and scrub the potatoes, then dry them thoroughly. Use a mandoline slicer to cut the potatoes into thin slices.
- Simmer until tender. Put the sliced potatoes into a pot and pour in enough water to cover them by 1 inch. Bring the water to a boil, add the salt, then lower the heat. Simmer for about 6 minutes or so, until the potatoes are tender enough to pierce with a fork.
- Whisk the vinaigrette. Add the extra virgin olive oil, white wine vinegar, Dijon mustard, ground sumac, black pepper and ground coriander to a small bowl. Whisk until the dressing is well combined.
- Dress the warm potatoes. Once the potatoes are tender, take them off the heat and drain them thoroughly. Transfer them to a large mixing bowl and immediately pour over the Dijon mustard dressing. Toss gently so the thin potato slices are coated without breaking them apart.
- Add the fresh ingredients. Add the chopped red onions, fresh parsley, dill and capers. Gently toss again until they are distributed through the potatoes.
- Rest before serving. Move the salad to a serving platter and give it some time to marinate before serving. You can refrigerate it for 1 hour or so, but bring it back to room temperature before serving.
Mustard Potato Salad
Ingredients
Method
- Prepare the potatoes. Wash and scrub the potatoes, then dry them thoroughly. Use a mandoline slicer to cut the potatoes into thin slices.
- Simmer until tender. Put the sliced potatoes into a pot and pour in enough water to cover them by 1 inch. Bring the water to a boil, add the salt, then lower the heat. Simmer for about 6 minutes or so, until the potatoes are tender enough to pierce with a fork.
- Whisk the vinaigrette. Add the extra virgin olive oil, white wine vinegar, Dijon mustard, ground sumac, black pepper and ground coriander to a small bowl. Whisk until the dressing is well combined.
- Dress the warm potatoes. Once the potatoes are tender, take them off the heat and drain them thoroughly. Transfer them to a large mixing bowl and immediately pour over the Dijon mustard dressing. Toss gently so the thin potato slices are coated without breaking them apart.
- Add the fresh ingredients. Add the chopped red onions, fresh parsley, dill and capers. Gently toss again until they are distributed through the potatoes.
- Rest before serving. Move the salad to a serving platter and give it some time to marinate before serving. You can refrigerate it for 1 hour or so, but bring it back to room temperature before serving.
Notes
Making The Salad Ahead
You can prepare this mustard potato salad in advance, but the supplied recipe recommends splitting the process slightly. Dress the cooked potatoes with the vinaigrette first, then hold back the onions, herbs and capers. The dressed potatoes can be refrigerated for up to 8 hours. Before serving, add the red onions, parsley, dill and capers, then toss everything together. This keeps the fresh additions separate until closer to serving while still allowing you to handle the potato and dressing portion earlier. Leftovers can be kept covered in the refrigerator for 2 to 3 days or so, according to the supplied recipe notes.How To Keep The Potatoes From Breaking Apart
The biggest texture risk with this recipe comes from the combination of thin slicing and simmering. The potatoes need to become tender enough to pierce with a fork, but once they reach that point, they’ll also be more delicate.
Start by keeping the slices similar in thickness. That reduces the chance of some pieces becoming very soft while others are still firm.
Drain the potatoes as soon as they reach the supplied tenderness cue. Then use gentle movements when mixing in the vinaigrette and again when adding the onion, herbs and capers.
The aim isn’t to aggressively stir the salad. You only need enough movement to coat and combine the ingredients.
Making The Salad Ahead
You can prepare this mustard potato salad in advance, but the supplied recipe recommends splitting the process slightly.
Dress the cooked potatoes with the vinaigrette first, then hold back the onions, herbs and capers. The dressed potatoes can be refrigerated for up to 8 hours. Before serving, add the red onions, parsley, dill and capers, then toss everything together.
This keeps the fresh additions separate until closer to serving while still allowing you to handle the potato and dressing portion earlier.
Leftovers can be kept covered in the refrigerator for 2 to 3 days or so, according to the supplied recipe notes.
Recipe Notes
A few details are worth keeping in mind when preparing the salad.
The recipe makes 8 servings and provides 150 kcal per serving.
New potatoes, Yukon gold potatoes or red potatoes are all specifically listed as options in the recipe. Whichever one you use, the potatoes should still be sliced thinly before cooking.
For the best result, don’t skip the resting period. The salad can be refrigerated for 1 hour or so after assembly, then brought to room temperature before serving.
Frequently Asked Questions
Can I make mustard potato salad ahead of time?
Yes. The supplied make-ahead method recommends dressing the potatoes with the vinaigrette first while leaving out the onions, herbs and capers. Refrigerate the dressed potatoes for up to 8 hours, then add the remaining ingredients before serving.
Which potatoes can I use?
The ingredient list specifically suggests small new potatoes, Yukon gold potatoes or red potatoes. Keep the preparation the same and slice them thinly before simmering.
How do I know when the potatoes are ready?
After the water comes to a boil and the salt is added, reduce the heat and let the potatoes simmer for about 6 minutes or so. They’re ready when you can pierce them with a fork.
Should mustard potato salad be served cold?
This version can be refrigerated for about 1 hour after assembly, but the recipe instructs you to bring it back to room temperature before serving.
How long will leftovers keep?
Store leftovers covered in the refrigerator for 2 to 3 days or so, according to the supplied recipe notes.
Final Thoughts
This mustard potato salad is all about the contrast between soft, thinly sliced potatoes and a lively Dijon vinaigrette. Fresh dill, parsley, red onion and capers keep the flavour bright, while dressing the potatoes immediately after draining helps the vinaigrette become part of the salad rather than simply sitting on top.
