Make a vinaigrette from vinegar, oil, mustard and spices with a small whisk or in a shaker. Mix well with the diced paprika, the diced apples and the chopped onion or shallot. Let it steep briefly.
Mix in the tomatoes and season to taste before serving. Cover a salad bowl or plate with beautiful washed lettuce leaves, spread the apple and pepper salad on top and sprinkle everything with chopped walnuts.