Heat oil in a pot over medium heat and sauté onion until golden.
Add garlic, ginger, berbere, and tomato paste; cook until fragrant.
Stir in lentils, water, and coconut milk; bring to a boil.
Reduce heat and simmer, stirring occasionally, until lentils are tender and sauce is creamy, about 25 minutes.
Season with salt, stir in chopped cilantro, and serve hot.