1small can5.5 oz / 156 ml tomato paste (about 1/2 cup / 125 ml)
4cupscooked black beansor two 19 oz / 540 ml cans
4cups/ 1 liter vegetable stock
1cup/ 250 ml salsa
1tablespoon/ 15 ml oregano
1/2teaspoon/ 2.5 ml salt
1/4teaspoon/ 1.25 ml pepper
1tablespoon/ 15 ml lime juice
Heat a frying pan over medium heat. Add oil and stir to coat pan. Add onions and cook 2-3 minutes until onions are soft. Do not let onions brown. If they start to brown, turn down the heat. Add garlic and 1/2 teaspoon / 2.5 ml salt and cook for 1-2 minutes more.
Add chili powder, cumin and coriander and stir to coat vegetables. Cook, stirring frequently to prevent spices from burning, for 1-2 minutes. Add tomato paste and stir to combine thoroughly. Cook for another minute.
Add beans, vegetable stock, salsa, oregano, 1/2 teaspoon / 2.5 ml salt and pepper. Bring soup to a simmer on stovetop at medium-high heat, then reduce heat to medium-low. Cover and simmer for 30 - 40 minutes, or until soup has started to thicken.
Crush some of the beans with the back of a spoon or a potato ricer. Stir in lime juice and serve.
Slow cooker version:
After cooking the onions, garlic, spices and tomato paste, add all ingredients except lime juice to a 4.5 quart slow cooker and cook on high for 2-1/2 to 3 hours, or low for 5-6 hours.
You can omit the step of cooking the onions, spices and paste and simply add all ingredients (except lime juice) to the slow cooker.