Peel the asparagus, cut off the woody ends. Put the asparagus in boiling salted water and let it simmer for about 15 minutes. Wash the potatoes and cook in little boiling water for about 15 minutes. Meanwhile peel and finely chop the onion. Wash, clean and chop the mushrooms. Cut ham into fine strips. Sauté onion in hot fat, add mushrooms, fry for 3-5 minutes.
Season with salt and pepper. Add 200 ml asparagus stock, bring to the boil. Add sauce thickener, refine with crème fraîche. Heat the ham in it, season again. Drain potatoes, rinse and peel. Arrange asparagus with potatoes and sauce on a plate. Serve garnished with parsley