This recipe came from The Big Book of Preserving the Harvest by Carol W. Costenbader. This book has lots of lovely, easy recipes.
12 cups chopped tomatoes
1 TBSP olive oil
1 medium onion, chopped
2 cloves garlic, crushed
2 TBSP chopped green bell pepper
2 TBSP chopped carrot
2 TBSP chopped celery
2 TBSP chopped fresh parsley
1 tsp chopped fresh oregano
1. Wash, core, and coarsely chop the tomatoes
2. Puree in the bowl of a food processor
3. Heat the olive oil in a heavy saucepan and saute the onion until soft, about 5 mins
4. Add the garlic, pepper, carrot, celery and herbs.
5. Add the tomato puree to the mixture and simmer, uncovered, for about 2 hours. Be careful not to let it burn. Stir the sauce occasionally as it thickens. (This process can also be completed in an uncovered casserole dish at 180C/350F in the oven)
6. Cool slightly and pour the sauce into 1 cup freezer containers, leaving 1/2 inch of headspace, label and freeze for up to 3 months. OR ladle hot, simmering sauce into hot, sterile jars, leaving 1/4 inch head space, and seal.
Everything but the chopped onion and tomatoes is shown on the plate above.