Wash the pumpkin, cut into thin slices and remove the seeds. Cut the pumpkin with skin into small cubes. Peel onions and garlic and dice both finely.
Heat the oil in a large pan with a lid. Stir-fry the pumpkin, garlic and half of the onions for 3-4 minutes.
Pour on the tomatoes and juice and crush them into small pieces with a spatula. Bring to the boil, cover and simmer for about 10 minutes. Season with salt, pepper and 1 pinch of sugar.
For the filling, cut the chilli lengthwise, remove seeds, wash and chop finely. Knead minced meat, rest onion, chili, tomato paste and egg. Season with about 1 tsp salt and about 1/2 tsp pepper.
Preheat oven (electric cooker: 200°C/circulating air: 175°C/gas: level 3). Spread some tomato sauce in a square casserole dish. Place the cannelloni vertically and fill with chopped mass.
Place the cannelloni close together in the mould. Pour the rest of the sauce over the cannelloni. Cut mozzarella into slices. Sprinkle with goat's cheese in pieces. Bake in the oven for 40-45 minutes.