Combine oil and butter in a stock pot and heat over medium. Sauté onions until softened, then add apple, sweet potato, ginger, paprika, cumin, and chili powder. Stir to coat with oil and sauté for 3 minutes. Add lentils, water, and bouillon. Bring to a boil and cook until sweet potato is soft and lentils are tender.
Using an immersion blender, blend the soup until smooth. Serve with a spinach salad.