Peel, wash and dry the vegetables. Cut into large pieces and fry in butter in a saucepan. First, onions, carrots and sweet peppers. Stir occasionally and don't let it brown too much.
After about five minutes, add the melted butter and zucchini, cauliflower, garlic. Sprinkle with sugar. Stirring, continue baking.
Tomatoes are peeled and coarsely chopped. Add to the pan with vegetables. Pour half of the sauce and simmer under the lid for 5 minutes.
Pour in the broth. Bring to a boil and add the lentils, rubbed through a sieve.
Cook for 15 minutes until the lentils are soft.
Whisk the soup with an immersion blender.
Return the saucepan to the fire, pour in the second half of the soy sauce and sprinkle with curry powder, pepper and paprika. Stir, add salt to taste and bring to a boil.
Serve hot, seasoned with sour cream and garnished with herbs and chili pepper slices.
