I have been making these for 25 years or better & you can either just eat them straight from the fridge or use in chili or other dishes. I use them in chili, Italian soup, goulash, eat as a cold veggie at meals when we don't have fresh ones.
You could buy them in the stores but I never could find a recipe to can them myself so I just made one up. I looked on a can of them to see what all was in them & looked up a recipe for canning whole tomatoes & married the two together & this is what I came up with.
I also tried heating the veggies some before adding the whole tomatoes to heat so the whole tomatoes would stay whole better. I like it this way better.
Cut up celery, onions (slivers) bell pepper, & minced garlic (store bought is ok if you don’t have a lot of fresh) Keep garlic seperate. Don't add with veggies at this time. I use equal parts of all veggies & then add several Tb. of minced garlic to pot of tomatoes when I go to heat them.
When you cut the veggies just place them in a large bowl & scoop into tomatoes as much as is needed. Set aside for now.
Slip skins on tomatoes by plunging into boiling water for about 2-3 minutes, then plunging into a sink of cold water. This is refered to as shocking them. If you have stored the tomatoes in fridge until you have enough to can, set them out to get to room temp first. Core tomatoes & cut in half if large. If small, leave whole.
The white pan I have here held 11 quarts of stewed tomatoes.
Place 8 cups of your veggie mixture in large granite pot or stainless steel (not aluminum). To your pot of veggies, add about 4 or 5 of your large tomatoes that have been cut up & squeeze to make a juice. Just enough to barely cover veggies. Heat for about 10-15 minutes until it starts to give it up. Just heat through. You still want the veggies tender–crisp as they will cook more in the hot bath.
Add your prepared tomtoes & about 5 T. minced garlic to this size pot now & continue heating just until hot.
Fill quart jars adding 1/2 Tablespoon of canning salt per quart. Wipe jar rims so no food particles are on it. (I didn't say it was gonna be a neat job-refer to picture.)Place heated lids on just finger tight.
Hot bath for 10 minutes. Start timing when water comes to boil.