Gluten free broth is expensive and gluten free stock is near impossible to find, so I make all of my soups without either of those flavor-helpers. This is by far the best broth base I have ever created.
Cover the bottom of a large pan with a generous pour of olive oil. Thinly slice 1/2 of a red onion, mince 5 cloves of garlic, and add to olive oil with a generous--no wait, enormous--sprinkle of Italian spices, salt, and pepper.
While the onion and garlic soften, halve cherry tomatoes. Toss in after onions and garlic are transparent.
After cooking for a few more minutes, add 3 8 oz. cans of basic tomato sauce. Stir in several tablespoons of pesto and 2 15 oz. cans of canellini or other white beans, with their liquid.
After a few more minutes, add water, tasting the broth until you hit that sweet spot of slurpy goodness. Add more seasonings as needed, and let simmer. After awhile, stir in several large handfuls of spinach.
Serve with an extra drizzle of olive oil.