Peel and finely dice the onion and garlic. Heat the oil in a large pot. Sauté both in it. Steam the Italian herbs briefly. Add tomatoes and 1⁄2 l water. Stir in broth and macaroni.
Season with salt, pepper and 1⁄2-1 tsp. sugar. Bring to the boil and simmer over medium heat for 8-10 minutes. Stir several times in between, so that the noodles do not stick to the bottom of the pot.
Rinse the fish and cut into cubes of about 2 cm. Season with salt and pepper. Mix carefully with chili flakes into the noodles. Continue cooking for 2-3 minutes, trying in between so that the noodles do not get too soft.
Rinse the sprouts, drain well. Wash herbs, shake dry, pluck smaller. Add sour cream and mozzarella loosely to the noodles, season to taste again and serve. Sprinkle with herbs and sprouts.
Serve immediately as the noodles will follow in the sauce and quickly become too soft!