crockpot Italian sausage and veggie soup

This is one of my favorite soups! I love the flavor that the sausage lends to the broth, and I get unreasonably excited about adding big handfuls of fresh spinach at the end. This is a great recipe to play around with. You could use mild sausage or a combo of the two, use different veggies such as zucchini or mushrooms, swap the chicken broth for beef broth and/or use a different pasta than shells.

Crockpot Italian sausage and veggie soup (similar to this)
makes 8 servings

put the following into a large crockpot and cook on low for 6-8 hrs or on high for 4-5:
-3 to 5 links of cooked spicy Italian sausage (we find 3 is enough)
-1 chopped onion
-1 cup of chopped celery
-1 cup of chopped carrots
-1 can great northern beans, drained and rinsed
-1 can of Italian-style diced tomatoes, drained
-8 cups chicken broth- use more or less depending on how much broth you like. (I recommend using bouillon cubes or paste instead of canned or boxed broth. SO much cheaper!)
-3 cloves of garlic, minced
-several large pinches of Italian seasoning
-salt and pepper to taste

add before serving, if desired:
-fresh spinach
-1/2 box of cooked pasta shells (I recommend adding pasta to each serving as opposed to adding it to the crockpot—otherwise the pasta will overcook and become mushy.)
-cheese to add on top (we like mozzarella or cheddar)