Heat the olive oil in a saucepan. Peel the tomato and cut into small pieces.
Put the onions and carrots finely chopped into the saucepan. After 5 minutes add the chopped tomato and the crushed garlic cloves and sweat for another 3 to 5 minutes. Put the water in the pot. When the water boils add the stock cube, salt and lentils. Let the whole thing simmer for half an hour while stirring regularly (add a little water if necessary - the soup must not get too thick).
Then let the soup cool down a bit and then strain it through a fine sieve. Finally, season with the cumin and coriander, depending on your taste, a pinch of pepper (but also tastes good without), the lemon juice and, if necessary, more salt and / or vegetable stock or stock cubes. You should taste the cumin very clearly. Finally stir in the crème fraiche.
This lentil soup is wonderfully warm from the inside on cold days.