Strain the soaked lentils and boil them in water with the thyme and bay leaf for 5 minutes, then strain and remove the spices.
Peel and chop the onion and sauté in butter.
Dust with flour, mix well and pour in the vegetable soup. Simmer over medium heat for about 10 minutes.
Add the lentils, season with salt, pepper, garlic and refine the lentil soup with the whipped cream.