Finely dice the rolls. Wash and chop the tomatoes. Mix with bread roll cubes. Peel and finely dice onion. Heat butter in a pot and fry onion. Add milk, heat briefly. Add milk mixture to the rolls.
Mix everything well. Cover and leave to stand for about 30 minutes.
Wash basil, shake dry and chop leaves. Whisk eggs and 1 teaspoon salt. Add the basil and eggs to the roll mixture. Knead everything with your hands.
Bring plenty of salted water to the boil in a large wide pot. Form approx. 16 dumplings from the bread roll mixture. Let it simmer in water at low heat for about 15 minutes. Lift out dumplings and let them drain.