Although ten pounds of tomatoes sounds like a lot, roasting concentrates that into about 7-8 cups, enough for about 4 pint jars. One jar will serve 3-4 for dinner over pasta. This sauce will keep fresh in the refrigerator for 4-5 days. You can also freeze it or pressure-can it. To roast this many tomatoes at once, you will need to use two roasting pans so as not to crowd the ingredients while roasting. That may require two ovens or roasting in two batches. If you don’t own a roasting pan, find a friend who does and borrow one.
Pre-heat the oven (s) to 425 degrees (218C). Get out two large stainless steel roasting pans (like for roasting a turkey).
Wash the tomatoes. Depending on the type of tomato, you may need to cut out the core first, as with large Beefsteak or Heirloom varieties. Then, cut tomatoes into large chunks. Don’t cut the pieces too small. Big chunks are good. Smaller pieces might roast too fast.
Place tomatoes in the roasting pan. Add garlic cloves, oil, wine or broth, oregano, onion, salt and pepper. Toss with your hands. Place pans in the oven (s) and roast until tomatoes have reduced and are starting to get a few black edges. The pan should still have some juices, not be dry. Depending on your oven it should take 45-60 minutes. Stir half way through. If the tomatoes are really juicy, it may take longer.
Remove pans from oven, set on the stove top and allow to cool until you can handle it. Carefully transfer the roast tomatoes into a food processor and pulse 5-6 times. You can also use a blender and proess in batches. Serve or cool completely and freeze in portions
Canning tomatoes requires a pressure canner. See notes in the post.