You will need: 1 large onion, about 6-8 large ripe tomatoes, olive oil, 2-4 cloves of garlic, herbs, salt and pepper.
1. Thinly slice your onion and garlic and scatter them in a baking dish. Drizzle with olive oil and roast in the oven for about 10 minutes turning half way through (I use temp of 180°C).
2. Slice the tomatoes and place on top of the onion. Sprinkle with your herbs, salt & pepper (I used time here). Roast for another 15 minutes mixing half way through.
3. Blend together and there you have a super easy tomato sauce base