.....Make tomato sauce. I had more tomato slices than I did sliders last week, some pieces I didn't slice and a couple of tomatoes that were a little soft, so I made tomato sauce. It's very basic with not too much seasoning right now so you can flavor it anyway you want when you use in in other recipes. The garlic, basil and oregano add flavor to the sauce and is ready for whatever you want to do with it later on.
Cut or slice the tomatoes and spread out on a large, rimmed cookie sheet. Sprinkle all but 2 tablespoons of the oil over the tomatoes and about 1 teaspoon of the salt. Put in the oven for about 25 minutes.
Heat 2 tablespoons of the oil in a heavy, covered pot over medium high heat and add the onions, 1/2 teaspoon of the salt and 1/4 teaspoon of the pepper. Lower the heat to medium and cook until the onions are soft, 4 to 5 minutes. Add the garlic and combine. Turn the heat to low until the tomatoes are done.
Remove the tomatoes from the oven and spoon into the pot, with the liquid if you wish. Return the heat to medium high, add the San Marzano tomatoes, the tomato paste, basil, oregano and half of the remaining salt and pepper. Stir and bring to a boil, stirring occasionally. Cover, lower the heat to low and cook for 90 minutes, stirring occasionally.
Just before the 90 minutes are done, taste and add more salt and pepper if needed. Don't over season as you'll be adding more when you use it in other dishes.
Remove from the heat and let cool for a few minutes. Using an emersion blender right in the pan, blend until smooth. You can also do this in a blender in batches. Be careful with hot liquids in a blender. They tend to splash even with the cover on.
At this point you can pour it through a colander to catch little pieces you don't want in your sauce. Let cool further.
Divide the sauce between storage containers, glass jars, etc., cover tightly and refrigerate or freeze.