Black Bean Chipotle Soup

Ingredients
1 pound dry black beans
2 stalks celery, chopped
2 carrots, chopped
1 yellow onion, diced
2 chipotle peppers in adobo sauce, chopped
1 cup crushed tomatoes
1 can (4 oz.) chopped mild green chilies, drained
6 cups vegetable stock
2 teaspoons cumin
Salt and pepper to taste
Optional toppings:  sour cream, chunky-style salsa, fresh chopped cilantro
 Directions
Rinse and sort beans and place in large bowl; cover completely with water.  Soak 6 to 8 hours or overnight.  Drain beans; discard water
Place beans in a slow-cooker. 
Add all other ingredients.
Cover and cook on low for 7-8 hours or high for 4.5-5 hours
If desired, process mixture in blender, in 2 or 3 batches to desired consistency, or leave chunk.  Serve with optional toppings.