Peel the ginger and cut it into thin slices. Cut the mushrooms in 4. Peel and cut the pumpkin or butternut into large cubes.
Rinse both types of lentils in clear water in a colander. Pour them into a pot of salted water with the turmeric, about twice the volume of the lentils. Bring to a boil and cook over medium heat for 15 minutes.
Drain them almost completely and return them to the pan on the heat. Then add the coconut milk and green curry. Mix well with a spatula before adding the other ingredients: peeled ginger cut into pieces, kaffir lime leaves or combava peel, a few basil leaves, pieces of pumpkin or butternut, mushrooms cut into 4, chili, sugar and minced garlic. Cook for another 20 minutes, covered, stirring occasionally, then let stand for 15 minutes, covered, with the heat turned off. Lentils should be tender.
Adjust the seasoning, add very thin slices of red onion and serve with a few basil or coriander leaves as decoration.