Veggies: Finely chop the onion. Wash the cauliflower head and break it up into small florets (the smaller they are, the quicker they will cook). Cut the stem into slices, then into dice.
Sauté the onion and spices: Heat a large pot or skillet with olive oil. Sauté the onion until translucent. Then, add in the garam masala and fry for 1 minute to help it develop its aromas. Add a splash of water to prevent it from burning and help coat the cauliflower in the next step.
Pre-cook cauliflower: Add the cauliflower to the pot and give it a good stir. Cover with a lid and cook for 10 minutes over medium-high heat, stirring once or twice.
Simmer: Add in the lentils, diced tomatoes, coconut milk, and salt. Fill up an empty can with water and add it to the pot. Cover with a lid and simmer for 20 minutes over medium heat.
Cook the rice according to package directions in salted water.
Adjust seasoning with salt if needed. Serve with cooked basmati rice, naan bread, or warmed-up tortillas.