And it’s easy. Just put your fresh tomatoes in a cake or roasting pan, smother with olive oil, season with salt and pepper and slow roast overnight. Or for 5-6 hours on 250ºF. You can add garlic, sprigs of herbs, slices of carrot and onion, whatever you like, in your sauce. The skins will pucker and maybe blacken a little.
Then whizz them in the blender. Or if you don’t like the idea of the skins and seeds, put them through a sieve or food mill.
Use the sauce fresh. It’s delicious on pizzas and pasta. It’ll keep in the fridge for a couple of days. Or freeze it. (Freeze in muffin tins and pop them out and store in a Ziplock for handy-sized quantities.)
Want to stretch it a bit longer? Add a tablespoon of of bottled lemon juice to each pint, and 2 tablespoons to each quart. If it’s too citrusy, add some sugar to taste. It should be shelf-stable for a few months.
Want to can it? Tomatoes can be canned in a water bath canner (the non-pressure cooking type). Ladle your lemon-juiced tomato sauce into HOT glass canning/Mason jars.
Fill the jars until they have 1/2 inch of headspace (The gap between the sauce and the top of the jar.) Place them in boiling water and process (basically boil, the pint jars for 35 minutes and the quart jars for 45 minutes in the water bath. Remember, if you live above 1,000 ft you will need to adjust your canning time. (See here.)