Begin by soaking the mixed beans overnight in water.

Chop the onion, carrots, and celery into small pieces.

In a large pot, heat olive oil over medium heat. Add the chopped onion, carrots, and celery, cooking until softened for about 5 minutes.

Add minced garlic to the pot and sauté for another minute.

Drain the soaked beans and rinse them under cold water.

Add the drained beans, broth, thyme, smoked paprika, bay leaf, and diced tomatoes to the pot. Stir to combine.

Bring the mixture to a boil, then reduce the heat to low. Let the soup simmer for about 1 to 1.5 hours until the beans are tender.

Once the beans are soft, season the soup with salt and pepper to taste. Remove the bay leaf before serving.