Pantry scraps tomato soup. What should I have added?

I was craving grilled cheese and tomato soup today. Lacking canned soup or the ingredients to make a classic tomato soup, and not wanting to face the sub-zero temps I made do with what I had.

A can of V8, some salsa, roasted garlic, and a handful of shredded cheese blend.

It was pretty good, but really needed umami. Maybe I should have thrown some nutritional yeast in there? What else could I have added to give the makeshift soup more depth and richness?

Edit - Great suggestions. With what I have on hand i should have added Worcester sauce and msg, and slow cooked it to a v8 reduction, maybe starting with a roux.

I'll be picking up some things suggested here to have in the pantry. Tomato paste of course, which I usually have but am out of, fish sauce, black garlic, and tomato powder.

Thanks for the input everyone!