Here is my simple tomato sauce recipe, works perfectly with pasta dishes or when thickened can be used as a pizza sauce:
Blend 2-3 tomatoes, 1 capsicum, 1 green chili, small onion and a grated carrot together until smooth. Heat a bit of oil in a pan, like a tbsp. or even less. Then add a bit of garlic paste, followed by 1 tbsp. tomato paste.
Once that's cooked for a couple minutes, add the blended mixture and simmer. Add salt and a tsp. of sugar followed by a bit of tandoori masala or cumin powder or oregano or you can just leave it plain and unspiced according to your taste.
Let it simmer until thick and all the water is gone. Then use accordingly! :)