Buy a can of tomato paste. If you're in the US this should set you back less than a half buck.
The problem with tomato past is that while very useful, and is expressly called for in many recipes, it's mostly called for in small amounts, and then the rest of the can, even if you transfer it to another container, sits in the refrigerator until it turns brown and you throw it away.
Open the can now, while you're not making anything, and put the contents, (use a scraper to get into the corners,) into a freezer bag, (a quart zip lock should do.)
Flatten it, press out as much air as you can and freeze it.
Anytime you're cooking or heating almost any[savory]thing with more than 3 ingredients, break off a teaspoon-sized piece and add it. (Thaw if necessary, say, in hummus.)
It is compatible with a huge range of spice and flavoring palates, (is that the right "palate"?) and adds an often undefinable richness and depth to many foods.
If you don't believe me, add some to a chocolate cake batter some time.