Prep the Legumes: Rinse the red lentils, split peas, and mung beans thoroughly.
Place them in a large bowl and cover with hot water.
Let them soak for 30 minutes, then drain completely.
Cook the Dal: In a large saucepan, combine the drained lentil mixture, 6 cups (1440 ml) of water, 1 Tbs. of butter (or oil), 1 Tbs. of ginger, and the turmeric.
Bring to a boil, then reduce the heat, cover, and simmer for about 1 hour, or until the legumes are very soft and falling apart.
Finish the Dal Base: Once cooked, use a wire whisk to vigorously stir the dal, breaking up the lentils to create a creamy consistency.
Stir in the fresh spinach and 1 tsp. (5 ml) of salt.
Cover and let it simmer for another 10 minutes until the spinach is wilted.
Make the Tarka: While the dal simmers, heat the remaining 2 Tbs. of butter (or oil) in a small skillet over medium heat.
Add the whole cumin seeds and cook for 30-60 seconds until they darken and become fragrant. Be careful not to burn them!
Sauté the Aromatics: Add the chopped onion, garam masala, and cayenne pepper to the skillet.
Cook for 3 to 5 minutes, stirring occasionally, until the onions soften and start to brown.
Stir in the minced garlic and the remaining 1 Tbs. of ginger and cook for one more minute until fragrant.
Combine and Serve: Add the diced tomato to the skillet and cook for 2 to 3 minutes, until the tomato breaks down and releases its juices.
Pour this entire aromatic tarka mixture into the saucepan with the dal and stir to combine.
Taste and season with additional salt and pepper if needed.
Serve hot, garnished with fresh cilantro leaves if you like.
Adjust the Consistency: Dal will thicken as it cools. To reheat or achieve a thinner consistency, just stir in a splash of hot water until it reaches your desired texture.
