For the skewers, wash the potatoes and cook in boiling salted water for about 20 minutes. Drain potatoes, rinse with cold water and peel. Wash and peel the white asparagus and cut off the woody ends. Wash the green asparagus and cut off the woody ends. Cook white asparagus in boiling salted water for about 20 minutes. Add the green asparagus after about 8 minutes of cooking time and cook with it.
Wash the apples, cut them into quarters, cut out the core and cut the quarters into slices. Put them on skewers alternately with potatoes and bay leaves. Shortly before serving, fry in hot oil all around for about 4 minutes. For the sauce, mix mascarpone, cider and 75 ml asparagus stock and heat up. Season to taste with salt and pepper. Serve the asparagus, skewers and sauce garnished with laurel and thyme