Sauté the aromatics. Heat the butter and oil in a deep Dutch oven or pot over medium heat. Once hot, add the minced shallots, garlic, and ginger. Sauté for 2-3 minutes.
Add the spices. Next, add the ground spices and sauté for another 30 seconds. This will help intensify their flavors.
Add the lentils. To the pot, add the uncooked red lentils, diced tomatoes, tomato paste, water, salt, and sugar.
Let simmer. Bring to a boil and reduce to a simmer. Cover the pot with a lid and cook for 20-25 minutes, stirring 2-3 times during cooking to prevent the lentils from sticking to the bottom of the pot.
Add the coconut milk. Once the lentils are soft, pour in the coconut milk and stir to combine.
Simmer uncovered. Finally, simmer the curry uncovered, stirring regularly, for another 10-12 minutes or until it slightly thickens. Before serving, stir in the lime juice and a handful of chopped cilantro.
This red lentil curry will keep for up to 5 days in the refrigerator.
