Meanwhile, make the dressing: Put the egg yolks in a small bowl and break them up with a fork until no clumps remain. Add the mustard, lemon juice, vinegar, smoked paprika, salt and pepper, to taste, and whisk until smooth. Drizzle in the olive oil, while whisking, to make a creamy dressing. Arrange the asparagus on serving plates. Chop the egg whites and sprinkle them over the asparagus along with the lemon zest and capers. Drizzle with the dressing and top with freshly ground black pepper, to taste. Serve warm, room temperature or chilled.