Heat the oil in a pot, then add the mustard seeds and cumin seeds. Stir, then add the onion. Cover the pot and cook until the onion softens.

Add the garlic and half of the ginger. Stir, then add the tomato and spices. Pour in water and bring to a boil.

Add the remaining ginger, yellow lentils, and red lentils. Add more water as needed and cook for 15 minutes, or until the lentils are tender.

Add 2 tablespoons of chopped cilantro and the lemon juice.

Blend the soup in a blender if you prefer a smooth texture, or leave it chunky if you like.

Serve in bowls and garnish with the remaining cilantro. Enjoy!