Dice the onions and fry them briefly in hot oil in a saucepan. Peel and dice sweet potatoes and carrots and sweat briefly together with the lentils, then add 1.5 l of boiling water. Finely grate the ginger and add to the soup. Add turmeric and pepper. After about 15-20 minutes of cooking time, when the lentils are soft, puree everything. Then add coconut milk, orange juice and thyme and season with salt and pepper.