Heat the olive oil in a large pot, add one diced onion, and sauté for 4 minutes. Add two diced carrots and one diced potato to the pot. Sauté for 4 minutes, stirring occasionally. Add 2 garlic cloves and stir, 1 tbsp of tomato paste, 1 tsp of cumin, salt, and black pepper. Stir for 30 seconds and then deglaze the bottom of the pot with a small amount of chicken or vegetable stock. Add ca 1 liter of stock and 1 cup of lentils. Reduce the heat and allow to simmer for 30 minutes, stirring occasionally. If the soup gets too thick, add up to 1 cup of water, and blend. Squeeze quite some lemon over the soup and happy boat cooking!