Panera Broccoli Cheese Soup

This recipe is from my sister in law Michelle. I've tried lots of broccoli cheese soups and this one was the best. I made it before rushing to the church for a meeting and I forgot to add the cheese at the end.  The boys seemed to still like it and there was only a little leftover for me to have when I got home. Luckily I remembered to add the cheese to mine. :) Serve with homemade rolls.

 I would recommend doubling this if you want leftovers. it made just barely enough for us.

1T butter
1/2 onion
1/4 c butter
2 c milk
1/4 c flour
2 c chicken stock
1.5 c chopped broccoli
1 c. matchstick carrots
1 celery stalk, chopped
2.5 c grated cheese
salt and pepper

Saute onion and butter until tender. Set aside. Whisk melted butter and flour in pot, add milk if needed for 3-4 minutes. Add milk and stock and cook about 20 minutes. Add veggies and cook for about another 20 minutes. Stir in cheese and salt nad pepper.