Italian Potato Soup

I tried to re-create a soup we had at an Italian Restaurant. It turned out easy and tasty!

These are the ingredients:
1 package Italian sausage (1 to 1 1/2 lb)
1 onion
1 3 lb bag red potatoes
soup base, or bullion cubes, or broth (I use Better Than Bullion chicken or vegetable flavor)
1 pint half and half ( or milk)
2 oz arugula
oyster crackers

Here's how to do it.
Break the sausage into small pieces and cook.
Chop the onion and add to the sausage toward the end of the cooking.
Wash and slice the potatoes and add to pan after onions are translucent. Add enough water to barely cover (about 4-5 cups) and some soup base (about 2 Tbs) and cook until the potatoes are done. ( about 10 mins or so).
Add the half and half.
Add about 2 oz of arugula. (that's about half of a bag)
Serve with oyster crackers.
This makes about 8 servings.