Peel onions and garlic. Chop the onions finely, press the garlic through a garlic press. Heat the oil. Fry half of the onions and garlic in it. Add spinach and steam for 5 minutes. Season with salt and pepper, drain well.
Drain the tomatoes. Finely chop the flesh. Peel, wash and chop the carrots. Melt butter. Fry remaining onions and garlic and carrots. Sweat flour and tomato paste in it. Deglaze with cream and tomato liquid, cook for 2-3 minutes. Wash basil, dab dry and chop. Stir chopped tomatoes and basil into the sauce. Season with salt, pepper, vinegar and sugar. Mix spinach and ricotta, season again. Pour into the cannelloni.
Deglaze with cream and tomato liquid, cook for 2-3 minutes. Wash basil, dab dry and chop. Stir chopped tomatoes and basil into the sauce. Season with salt, pepper, vinegar and sugar. Mix spinach and ricotta, season again. Pour into the cannelloni. Place the cannelloni in an ovenproof dish. Pour tomato sauce over them and sprinkle with parmesan. Bake in a preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for 20 minutes. Cut mozzarella into thin slices. Spread on the cannelloni and bake for another 15-20 minutes at the same temperature. Serve garnished with olives and basil
Place the cannelloni in an ovenproof dish. Pour tomato sauce over them and sprinkle with parmesan. Bake in a preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for 20 minutes. Cut mozzarella into thin slices. Spread on the cannelloni and bake for another 15-20 minutes at the same temperature. Serve garnished with olives and basil