Prepare the pasta in boiling salted water according to the instructions on the packet. Bring cream and 250 ml broth to the boil. Mix 5 tablespoons of stock and starch until smooth and stir into the boiling liquid. Simmer sauce for 1-2 minutes, then remove from heat and allow to cool. Wash and peel the asparagus, cut off the woody ends and cut the asparagus into pieces about 2 cm long.
Clean, wash and slice the leek. Cut ham into strips. Drain the noodles. Wash and halve the cherry tomatoes. Heat the oil in a frying pan. Fry asparagus for 2-3 minutes at medium heat, add leek after 1 minute. Turn the noodles into 6 nests and put them in an ovenproof dish. Arrange vegetables and ham in the baking dish. Grate parmesan.
Fry asparagus for 2-3 minutes at medium heat, add leek after 1 minute. Turn the noodles into 6 nests and put them in an ovenproof dish. Arrange vegetables and ham in the baking dish. Grate parmesan. Stir egg yolk and parmesan into the sauce and season with salt and pepper. Pour the sauce over the casserole and bake in a preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas mark 3) for approx. 45 minutes