Simmer tomatoes, chile, and oil in a 4-quart heavy saucepan, uncovered, stirring occasionally, until sauce is thickened, about 1 1/2 hours.
During last 10 minutes of cooking, add garlic and stir sauce frequently to prevent scorching.
Remove from heat, then stir in basil, salt and pepper, to taste.
Force through food mill into a large bowl.
NotesCooks' note: Sauce may be frozen in sealed bags 3 months.