This is a quick, simple marinara sauce that will only be good if your tomatoes are ripe. If you have a food mill, you don’t have to peel and seed the tomatoes; you can just quarter them and put the sauce through the mill.
If using quartered tomatoes, put through the medium blade of a food mill. If you used peeled seeded tomatoes but want a sauce with a smooth, even texture, remove the basil sprigs and discard. Pulse the sauce in a food processor fitted with the steel blade.