Rinse lentils and set aside. In a large skillet over medium, sauté onion in Olive oil for 2 minutes. Add in ginger and garlic and cook for an additional 5 minutes or until onion is translucent. Add curry powder and cook for an additional minute. Mix in vegetable broth and lentils and bring to a boil, reduce heat to simmer. Cook, covered partially and stirring occasionally, until lentils are tender, about 30 minutes. When lentils are done, add kale in batches, stirring to wilt between additions. Stir in lemon juice and season with salt and pepper to taste.