Prep however many baking pans you need for your tomatoes, or will fit in your oven by spreading 1 tablespoons of olive oil on the bottom of each
Cut large tomatoes in half, core and slice off blossom ends. Set cut side down in oiled pans. For smaller tomatoes, simply slice the tops, core and set sliced top down in pan (the blossom ends of smaller tomatoes aren't usually noticeable, but if they are, go ahead and slice them off, too).
Fill the pan(s) with a single layer of tomatoes. It's okay for them to touch, but don't heap them on top of each other.
Sprinkle with a teaspoon or two of salt, if desired.
Roast for 40-45 minutes, turning half way through (in a non-convection oven) and rotating if using more than one pan until the tops of many tomatoes are blistering and puffing up.
Remove from oven and cool for about 10 minutes. While cooling, use tongs to remove blackened tomato skins if needed.
Spoon an even amount of tomatoes and juices into a blender or food processor, process until smooth and then transfer to freezer jars or containers, leaving 1-inch or more room at the top for expansion.
Add lids, label with name and date (I use masking tape and a sharpie) and freeze.
This sauce will last for a year or more in the freezer.
*Tomato pounds are approximate - fill your roasting pan in one layer with tomatoes. This makes about 2 quart jars per large roasting pan.Use this plain tomato sauce in any recipe that calls for a can of tomato sauce like soups, enchiladas and stews.