Wash the asparagus, peel and cut off the woody ends. Moisten tea towel, wrap asparagus and chill. Bring asparagus peel and 1.5 l cold water to the boil, cover and simmer over a low to medium heat for about 10 minutes. Pour the asparagus skins onto a sieve and collect the asparagus water
Put the asparagus water, 10 g butter, sugar and a little salt (1-1 1/2 teaspoons) in a wide large pot and bring to the boil. Add the asparagus, cover and cook over medium heat for about 15 minutes. Clean, wash and drain the mangetouts. Lift the asparagus out of the asparagus stock with a skimmer, drain well and place on a deep, ovenproof dish. Remove 200 ml asparagus stock. Add mangetouts to the remaining asparagus stock and simmer for about 3 minutes.
Mix cream and sauce powder in a saucepan. Add 200 ml asparagus water and bring to the boil while stirring. Cut 50 g cold butter into cubes, add and fold in until melted. Switch off the stove. Stir 35 g parmesan into the sauce and season with pepper and lemon juice. Drain sugar snap peas well and add to the asparagus on the plate. Pour the sauce over it, sprinkle with 40 g Parmesan. Bake in the preheated oven (electric cooker: 225 °C/ convection oven: 200 °C/ gas: level 4) for 10-15 minutes
Wash the turkey fillets, dab dry and cut into approx. 12 medallions. Wash parsley and basil, shake dry and cut into fine strips, except for a little bit for garnishing. Peel and finely chop the onion. Heat the oil in a large frying pan, fry the medallions for 5-6 minutes while turning them and season with salt and pepper. Remove from the pan. Fry the onion and diced ham in hot frying fat, turning briefly and mix with the herbs. Place the turkey medallions on the plate with the asparagus au gratin. Spread herb and ham crisp on the medallions and garnish with basil as desired. Serve with boiled potatoes