Cook the tortellini in plenty of boiling salted water for about 16 minutes (or according to package instructions). Drain well.
Peel and chop the onions. Heat 3 tablespoons of fat. Steam onions until translucent. Add flour and sweat. Stir in milk, about 1/2 l water and cream. Bring to the boil, stir in stock. Season to taste with salt, pepper and some sugar.
Dice the ham, fold in.
Clean and wash the zucchini, cut them in half lengthwise and slice them. Fry them in hot oil. Season with salt and pepper. Grate cheese.
Mix tortellini with ham sauce and zucchini in a greased oven dish. Sprinkle with cheese. Bake in the preheated oven (electric cooker: 200°C/circulating air: 175°C/gas: level 3) for 25-30 minutes. Garnish with rocket salad.