For the soup, peel and finely dice the onion. Wash and halve the tomatoes. Heat 1 tablespoon of oil in a saucepan. Fry the onion in it. Add tomato paste and sweat it on. Stir in lentils together with stock, cream, approx. 300 ml water and stock. Bring everything to the boil and simmer covered for about 10 minutes.
For the salmon in the meantime wash the dill, shake dry and cut finely. Wash the fish, dab dry and cut into strips. Sprinkle fish with dill and press on. Heat 1 tablespoon of oil in a pan. Fry the salmon on each side for about 2 minutes.
Add tomatoes to the soup and heat briefly. Season soup with salt and pepper. Serve with fish.