Wash tomatoes. Dip in boiling water 30–60 seconds or until skins split; dip in cold water, slip off skins, remove cores, and quarter.
Boil tomatoes uncovered 20 minutes, then press through a food mill or sieve.
Brown the ground meat. Add garlic, onion, celery or green pepper, and optional mushrooms; cook until vegetables are tender.
Combine meat and vegetables with tomato pulp. Add salt, oregano, parsley, black pepper, and brown sugar. Bring to a boil and simmer uncovered until thick enough for serving and reduced nearly by half, stirring frequently.
Fill hot jars, leaving 1-inch headspace.
Pressure can pints 60 minutes or quarts 70 minutes. Dial gauge: 11/12/13/14 psi at 0–2,000/2,001–4,000/4,001–6,000/6,001–8,000 ft. Weighted gauge: 10 psi at 0–1,000 ft and 15 psi above 1,000 ft.