Wash asparagus, peel, cut off pointy tips. Blanch in the boiling water with pinch of sugar and 1 teaspoon of butter for 8 minutes. Melt the remaining butter. Mix yolks, yogurt, wine and mustar,stirring for 3 minutes.Season with salt, pepper and Cayenne pepper. Preheat the oven to 230 degrees Celsius. Place asparagus into a baking form. Wash and dry salmon fillets, place onto vegetables. Salt, pepper, sprinkle with dill. Pour the sauce and bake for 10-15 minutes.