Wash, clean and, except for one, dice the tomatoes. Peel and finely dice the onion and garlic. Heat the oil. Sauté onion and garlic for about 4 minutes. Add tomatoes, bring to the boil and braise for another 10 minutes. Season to taste with salt, pepper and sugar
Wash the asparagus, cut off the woody ends. Pre-cook the lasagne sheets in portions in boiling salted water for about 3 minutes. Dice bread coarsely and grind finely in the universal chopper. Wash fish, dab dry and chop coarsely. Process to a farce in the universal chopper portion by portion. Mix egg, breadcrumbs and fish. Season with salt, pepper and lemon juice
Place lasagne sheets next to each other on the work surface. Cover with fish farce and asparagus. Roll up the lasagne sheets. Arrange tomato ragout and cannelloni in a casserole dish. Finely grate the Parmesan cheese. Cut mozzarella into slices. Cut the rest of the tomato into slices. Spread cheese and tomato slices on the cannelloni. Bake in a preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: see manufacturer) for approx. 40 minutes