Wash tomatoes.

Core tomatoes.

Cut tomatoes in half and lay them cut side down on baking sheet.

Layer onion, peppers, and garlic cloves on top of tomatoes and sprinkle lightly with olive oil.

Place baking sheets in oven for 45 minutes.

You can easily pull tomato skins off at this point. Then scoop tomatoes, onions, and peppers only into your blender leaving juice in the baking sheet. (Tomatoes are mostly water)

Blend thoroughly. You may add tomato paste to tomato sauce after blending for desired sauce thickness or cook down in a pan on the stove top. Hopefully, you won't have to do neither.

After cooling, I taste to see if more salt,, garlic, or onion powder is needed for flavor.. Then I spoon my tomato sauce into food saver bags and lay flat in the freezer. You may opt for freezer containers. Will not keep for more than a week or two in the refrigerator in a glass container.