This is almost too easy.
Chop onion, sautee gently.
Add grated ginger, crushed garlic, chopped chilli(s). Sautee until onion is soft & translucent.
Add curry powder (garam masala, coriander, cumin, turmeric), sautee while stirring until aromas are released
Add cooked lentils (I like a mix of green and brown, but use your preference) and a couple of chopped, tinned tomatoes plus some of the juice
Turn up the heat and stir, simmer for about ten minutes.
Serve with naan bread.
Note: try adding tinned or fresh spinach to this.