Heat the same pan you used to cook the sausage to medium high, adding a swirl of olive oil to the pan, then add your peppers and onions, along with some salt and pepper. Saute the veggies for 5-10 till soften, giving them a stir every now and then.
Once the peppers and onions are done, combine them with the beans, and the sausage, in a large casserole dish.
*Tip- I like to add a couple table spoons of water to the mix as well, but is not needed. Also this is a great make ahead dish,you can just pop in the oven when you are ready.
Bake for 25-30 minutes till its a little bubbly, enjoy!