In a large pot, heat the olive oil over medium heat. Add the chopped onion and sauté for 3-4 minutes until softened.
1 tbsp olive oil, 1 onion
Add the minced garlic and grated ginger. Cook for another minute until fragrant.
2 cloves garlic, 1 tbsp ginger
Stir in the garam masala, turmeric, and cayenne (if using), cooking for 1-2 minutes to release the spices' flavors.
1 ½ tsp garam masala, ½ tsp turmeric, ¼ tsp cayenne pepper
Add the rinsed lentils, diced tomatoes, and vegetable broth (or water). Bring to a boil, then reduce the heat to low and simmer for 20 minutes, stirring occasionally.
1 cup red lentils, 14 oz tomatoes, 3 cups vegetable broth
Stir in the canned coconut milk and chopped spinach. Continue cooking for another 5 minutes until the spinach wilts and the dahl thickens.
½ cup coconut milk, 2 cups spinach
Stir in the lemon juice, adjusting the seasoning with salt and pepper as needed.
1/2 lemon, ⅛ tsp salt
Serve hot, garnished with fresh cilantro if desired.
1 handful cilantro