Peel, wash and roughly dice the potatoes. Cook in salt water for about 10 minutes. Peel and chop the onion. Cut bacon into strips. Press sausage meat out of the skin.
Heat 1 tablespoon of oil in a large frying pan. Fry the sausage meat and bacon for about 5 minutes. Use a spatula to divide into small pieces. Remove from the pan.
Drain the potatoes and let them drip off. Heat 2 tablespoons of oil in a frying pan. Fry the potatoes for approx. 10 minutes, turning them over, and add the diced onion for 3-5 minutes. Wash thyme, shake dry, remove leaves from the stems and chop. Season Gröstl with thyme, salt and pepper.
Wash, clean and roughly dice the tomatoes. Add the sausage-bacon mixture and tomatoes to the pan. Fry for another 5 minutes. Press 4 depressions into the Gröstl and beat in 1 egg each. Cover and allow to set for 2-3 minutes. Serve immediately.