Place beans in a large bowl.

Add enough cold water to cover the beans by 3 inches and soak overnight.

Drain the beans and transfer them to a heavy large pot.

Add 4 1/2 cups of water, chopped onion, chopped carrot, chopped bacon, fresh thyme sprigs, minced garlic, and bay leaf.

Stir in ground cumin.

Bring the mixture to a boil.

Reduce heat, cover, and simmer until the beans are very tender, stirring occasionally, for about 1 hour 10 minutes.

Working in batches, puree the soup in a blender with 2 cups of chicken stock.

Return the pureed soup to the pot.

Stir in chopped fresh cilantro.

Bring the soup to a simmer, thinning with additional chicken stock if necessary.

Season to taste with salt and pepper.