Saute onions in a large pot with about 2 tablespoons of olive oil. When onions have become translucent add the two jars of marina sauce, and can of chopped tomatoes, and turn down to simmer.
In a large skillet brown ground beef and Italian sausage until completely cooked, drain fat from meat, and add meat into the large pot with the sauce. Add chopped pepperoni to the sauce mixture. Add 1 teaspoon of Italian seasonings to the mixture and all to simmer for about 20 minutes before you season to taste with salt and pepper.
This makes a very large pot of sauce, if you have a larger family, consider stretching the sauce with an additional jar of marinara, or a can of tomatoes.
Since we are adding so many different spicy meats, wait until the all of the meats season the sauce before making any adjustments.
If you have a smaller family, you may want to freeze this sauce, and use later.