Crockpot red bean and sweet potato chili

I've been on a crockpot kick lately. (Can you tell?) I also paid off one of my student loans the other day. Which is awesome, but it means I have no cash to go grocery shopping with. That isn't really a problem--I have a fully stocked pantry, as you know--but I am completely out of green things, even frozen spinach, and I'm starting to run low on other basics.

In the meantime, I'm trying to get nutrients without greenery. This combination of red beans, sweet potatoes and tomatoes has lots of vitamins and such, and best of all, requires a bare minimum of effort to throw together. That's why I've been using my crockpot so much lately--been eating a lot of beans and lentils, because it's the end of the month, and because I'm lazy.

1 onion, chopped
1 garlic clove, chopped
1 bell pepper, chopped (I used 1 1/4 jarred roasted red peppers)
6 small sweet potatoes, peeled and diced
4 cups pre-cooked red beans
1 14.5 oz can tomatoes, with juice
Chili powder, cumin and cayenne to taste (I used 2 tablespoons, 1 tablespoon and a healthy sprinkle, respectively)
Broth

Saute the onion, pepper and garlic in olive oil in a skillet (on the stove) until soft. Add the seasonings and the sweet potatoes, and cook for another minute. Dump all this into the crockpot and add the beans, tomatoes, and enough broth to cover. Cook on Low for 6 hours. Salt and pepper to taste.