Heat 1/4 cup of olive oil on medium in the soup pot, add carrots, sweet potato, and zucchini. Cook until softened, about 5 minutes. Add the slightly crispy onions, curry powder, paprika, and garlic and stir for 2 minutes. Add the cooked lentils, bay leaf, tomatoes, and the rest of the chicken stock. Bring to a boil, cover, reduce heat to a simmer until lentils have completely softened, about 45 minutes, stirring occasionally.