Beef isn't just for burgers! Turn it into a sweet and spicy curried soup.
In a large pot, heat the oil over medium. Add the onion and cook, stirring often, until softened, 7 to 9 minutes. Add the ginger and curry powder and cook for 1 minute more. Add the beef and cook, breaking up the meat with a wooden spoon, until browned, about 5 minutes.
Stir in the lentils and tomato paste. Stir for 1 minute, then add 3 1/2 cups water, the coconut milk, and chopped cilantro. Season the soup with salt and pepper. Bring to a simmer. Cook until the lentils are tender, 20 to 25 minutes; season.
Off heat, stir in the lemon juice. Divide the soup among bowls. Top each with a dollop of yogurt and some cilantro leaves.