Steps:

Rinse lentils under cold water until the water runs clear.
In a large pot, heat the vegetable oil over medium heat. Add the chopped onion and cook until it becomes translucent.
Add the garlic, ginger, turmeric, cumin, coriander, and chili powder. Stir well to combine and cook for another minute to release the flavors.
Add the diced tomatoes to the pot and cook until they begin to break down and blend with the spices.
Stir in the lentils and add the water. Bring to a boil, then reduce the heat to low and simmer for about 25-30 minutes until the lentils are tender.
Adjust seasoning as needed before serving hot with rice or naan.

Lentil and Spinach Curry