Directions:

Chop onion and garlic, microwave for five minutes (omit this step if you don't have a microwave; it isn't essential but it makes the sauce quicker to cook).

Transfer to saucepan, add tomato puree and stir. Add tinned tomatoes. Season, bring to boil, and simmer for about 15-20 minutes until it has reduced to a jammy consistency. For seasoning, I use salt, freshly milled black pepper, Worcestershire sauce and some sort of herbs; fresh basil if I have it, or dried Italian seasoning.