In a large pot over medium-high heat, heat the oil. Saute the onion, garlic, carrots, and celery until the vegetables are tender, for about five minutes.
Add broth (for broth I used six cups of water and three bullion cubes), barley, cans of beans, can of diced tomatoes, tomato paste, and spices, and let it boil for 30 minutes until the barley is nice and soft.
If you have a crockpot and want to put it to good use, then this soup is a great option. Start by throwing in all the ingredients and letting it sit for the day on medium heat. If you are doing it this way, we recommend using pre-soaked bulk dry beans to keep the cost even lower. This is a great way to get into the habit of buying beans and pulses in the bulk section which would not only lower the cost but help you reduce waste.