Like clockwork, my Italian grandmother made a large pot of tomato sauce twice a week, every week. The sauce made on Sunday morning was served over pasta for our ritual Sunday lunch. Leftover sauce—she always made extra—went into the fridge and became an ingredient in other meals over the next few days. By Wednesday, the sauce was used up and she made a second pot.
Although she lived in a different era, my grandmother's efficient strategy of cooking makes a lot of sense today. Like her, I'm never without a supply of tomato sauce. It takes less than an hour to whip up a new batch, so it's easy to make more when I run low. The sauce goes into my soups and stews, it becomes a braising liquid for meats and, with a few added ingredients, it can turn into any of several richly flavored pasta sauces. I use my tomato sauce in place of canned tomatoes, and since it's already seasoned and reduced, it saves time during cooking. In short, my stash of frozen tomato sauce lets me put delicious homemade meals on the dinner table faster since I don't have to start from scratch every time.
Use marinara in braises and stews in place of canned tomatoes when you want to save time. Because the sauce is already seasoned and concentrated, the total cooking time is shorter.