Wash and dry chiles. Slit peppers and blister skins using the tested oven, broiler, or range-top method; cool under a damp cloth, slip off skins, discard seeds, and chop.

Wash tomatoes. Dip in boiling water 30–60 seconds or until skins split, cool in cold water, peel, core, and coarsely chop.

Combine tomatoes, peppers, onions, salt, oregano, and 5% vinegar in a large saucepan. Bring to a boil, cover, and simmer 10 minutes.

Fill hot jars, leaving 1 inch headspace. Adjust lids.

Process pints 20 minutes or quarts 25 minutes in a pressure canner at the source-specified pressure, adjusting pressure for altitude.