1. Mince the onion. Peel and dice tomato. Cut carrot into rounds.
2. Wash and drain the lentils. Put them into a soup pot and add the vegetables.
3. Pour 1200 ml of cold water and bring it to boiling over high heat. Then reduce the temperature to the lowest and cook covered until lentils become soft and tender. The soup will be quite thick at this point as lentils absorb the water.
4. Pour the oil into a small frying pan and add flour. Mix until fully combined. Heat the mixture over medium heat, stirring often. As the mixture heats it will become foamy. It'd done when the foam disappears. As I said, you should stir often so that the flour doesn't burn. Remove from fire, add paprika and combine. It should look like this (before you add paprika):
Serve warm with some bread and fresh salad. This tomato salad goes perfectly with it. Fresh peppers are also a great "side dish".
I, personally, love eating this soup with bread with some butter spread on it.
Enjoy and bon appétit!