Begin by preparing your apples, which is a pivotal first step to prevent browning. Core and dice 1 lb (500g) of crisp red-skinned apples, then immediately place them into a bowl and pour the juice of ½ lemon over the top.
Stir thoroughly to coat all the apple pieces completely—this lemon juice acts as a defensive barrier against oxidation. Once the apples are well-coated, transfer them to your serving salad bowl and add the 4 celery stalks that you've thickly sliced.
Next, add the creamy element that binds the salad together. Spoon ⅔ cup of mayonnaise over the salad mixture, then season with salt and black pepper to taste. Gently toss everything together until the ingredients are evenly coated and well-mixed.
At this point, cover the salad and refrigerate it until you're ready to serve. This chilling period allows the flavors to meld and helps maintain the salad's crispness and freshness.
Just before serving, stir in the ¾ cup of coarsely chopped walnut pieces and garnish generously with fresh chopped parsley. This timing is vital—adding the walnuts at the last moment guarantees they maintain their satisfying crunch rather than becoming soggy from the mayonnaise.
Serve immediately while the textures remain at their best.
