1/8 - 1/4teaspooncrushed red pepper flakes, to taste, for a bit of heat
Salt and freshly ground pepper
Soup:
2Tablespoonsolive oil
1/2cuponion, diced
3clovesgarlic, thinly sliced
4cupschicken or vegetable broth
16ozcanned red kidney beans, well rinsed
16ozcanned white kidney beans, well rinsed
1Tablespoonwhite or red wine vinegar
2teaspoonsdried basil
1teaspoondried thyme
1/2teaspoondried oregano
Pieceof Parmesan rind, optional
3cupsbaby spinach
1Tablespoonpesto, optional
Instructions
Heat 2 Tablespoons of oil in a large heavy pot over medium-high. Drain tomatoes, reserving the liquid to use later. Add the tomatoes, red pepper flakes and a pinch of salt to the pot. Stir to combine, then allow to cook, undisturbed, until caramelized and browning in spots, about 5 minutes. Break up tomatoes, scraping the bottom of the pot, and continue to cook, scraping and stirring occasionally, until tomatoes are caramelized all over, about 5 minutes more. Transfer tomatoes to a plate.
Heat another 2 Tablespoons of oil in the same pot over medium heat. Add onion, garlic, and a pinch of red pepper flakes if you like. Cook, stirring often, until vegetables are soft and starting to brown around the edges, 8-10 minutes. Stir in vinegar and caramelized tomatoes, scraping up browned bits. Add broth, beans, vinegar, dried herbs, reserved tomato juice and Parmesan rind (if using) to the pot. Bring to a simmer. Cook until flavours meld, about 30–45 minutes. Taste soup and season with salt and pepper, as needed.
Just before serving, stir in spinach and pesto, if using and cook until spinach is just wilted. Serve.
Notes
Tips!
Bringing out the full flavour of the tomatoes is the key to this soup. Taking the time to caramelize them at the beginning will really pay off at the end. Alternately, for a speedier soup, start with a can of Fire-Roasted tomatoes.
Be sure to rinse the canned beans well with cold water before using. You'll remove a lot of the added salt by doing this simple step.
As with all soups, seasoning with enough salt is key. If the soup seems to lack enough flavour, it probably needs more salt to bring out all the flavours.
See the notes above this Recipe Card for more tips for making this soup!