Use the food processor for salsa. It’s not going to be pretty anyway.
Basically, everything is going to go into a big pot to be cooked. It doesn’t really matter in what order the ingredients go into the pot. I tend to put the vinegar, tomato paste (in glass jars, no BPA!) and spices in first, if only because I’m afraid I’ll forget them at the end and have an incredibly boring (and unsafe) batch of salsa!
Moving on to the food processor, I start with the garlic because you really want that minced well, then onion. Adding some or all red onion is just lovely, and tastes great too.
The peppers come next. After a good scrub, I cut out the seeds, quarter them, and toss them into the food processor. Pulse.
I like to switch up the green a little and definitely mix red peppers, and sometimes even bananas or Anaheims if I have them.
If you want your salsa to have a shot at looking pretty, go ahead and dice the Romas. Otherwise food process gently.
Cook the salsa until it’s nice and hot (boiling), and then follow the instructions in my post about canning tomatoes (it’s important to clean and fill jars correctly if you’ve not canned before!). If it seems too juicy, you can always boil off some of the water.
Process 35 minutes for pints and 40 minutes for quarts.