Broccoli cheese soup

--1 qt chicken broth
--2 cups milk
--2 10 oz bags of frozen broccoli florets
--1/2 diced white onion
--1/2 t black pepper
--1/2 t salt
--1/2 t ground nutmeg
--1 cup each of three different cheeses, I used cheddar, jack, and mozarella. I don't think the mozarella worked very well and will try something else next time.
Mix everything except cheese in the slow cooker and cook on low for 7 hours. Mix in grated cheese 30 min before serving to melt.