Cut the stems out of the tomatoes. Roughly dice tomatoes. Steam the bacon and onions until translucent. Add tomatoes and meat stock and cook for 10-15 minutes.
In the meantime, finely chop the basil and set aside a few leaves for garnish. Bring the milk, butter and salt to the boil, add the flour. Stir until a dough ball loosens from the bottom. Put in a bowl, let cool down a bit and fold in the egg. Knead the almost cooled dough with the basil and form small dumplings.
Strain the soup through a sieve and let the dumplings steep in it over a mild heat. When they`re done, they swim up. Serve the soup sprinkled with basil.