10-11 pounds fresh tomatoes (this should make about 8 pints of sauce)
6 tablespoons olive oil
3 medium onions, diced
6 garlic cloves, minced
1/2 cup chopped fresh herbs or 2 tablespoons dried oregano, basil, and thyme
Salt and pepper to taste
Prepare the tomatoes: Have a large bowl filled with cold water ready and waiting. Set a large pot of water over high heat and bring to a rolling boil. Working in batches, drop the tomatoes in one at a time, then let sit in the boiling water until the skins split open, 30-60 seconds. One at a time, remove tomatoes from hot water with a slotted spoon and transfer to the bowl of cold water. When cool enough to touch, slip off and discard the tomato skins and remove the hard stem end and core. Trim away any bad spots. Roughly chop the tomato using a food processor or blender, a knife, or by squishing with clean hands. Set aside.
Make the sauce: Add the olive oil to an extra-large 8-10 quart stock pot over medium-high heat. When the oil is shimmering, add the diced onions. Cook, stirring frequently with a large wooden spoon, until onions start to soften and turn golden, about 8 minutes. Add the garlic and cook for another 30-60 seconds, stirring constantly so it doesn't burn. Add the fresh tomatoes. Bring just to a boil, then lower heat to medium-low and let simmer, uncovered, for 2-3 hours, until thickened. Stir occasionally to make sure the sauce at the bottom of the pan isn't burning. Add the herbs, salt, and pepper.
Freeze the sauce: Let the sauce cool completely. Pour into to freezer-safe containers or heavy-duty freezer bags. Label well with date and contents, or to storage containers with enough room to allow expansion, then transfer to the freezer. The sauce will last 3-4 months, or longer if you use a deep freeze.