As I mentioned a couple of days ago, I've been experimenting with giving up canned foods. I couldn't imagine giving up canned foods without having a replacement for canned, stewed tomatoes. I almost never buy pre-made sauces, so I've made my own red sauces with canned tomatoes.
With a slow cooker, however, it's easy (but messy!) to make your own stewed tomatoes. They can be frozen and used whenever you need them.
9-12 ripe tomatoes
1/2-1 yellow onion, chopped
2-4 cloves garlic, crushed or minced
Step 1: Prepare your space. You'll need a big pot, a small bowl for trash (skins, tomato innards, stems), a large bowl of ice water, and a bowl for your tomatoes. You'll also need a cutting board and knife. I'm not going to lie, the first time I tried this, I made a huge mess. But don't give up! The second time, I was able to keep the mess contained. Have your slow cooker ready (mine is 3.5 quarts).
Step 2: Blanch (or quickly boil) the tomatoes. Fill a large pot 2/3 with water, and get it boiling. Then -- carefully, so you don't burn yourself -- pour in the tomatoes. Leave them in the water for 2-3 minutes, or until the skins begin to split.
Step 3: Using a slotted spoon, transfer the tomatoes to the bowl of ice water. Wait a couple of minutes, until they are cool enough to touch.
Step 4: Peel and core the tomatoes. You should be able to simply pinch the peels and they'll come off. Discard the peels. Scoop out the tomato innards (seeds and liquid - if you don't, your stewed tomatoes will be too watery.) Chop the tomatoes if you want diced tomatoes; leave them whole if you want whole tomatoes ... I know, crazy, right?
Turn your slow cooker on low for 7-8 hours.
That's it! The tomatoes can be used just like any canned tomatoes. Freeze them in 2 cup portions and thaw when you're ready.