Broccoli Cheese Soup

2 10 oz cans Cream of Chicken soup
1 onion, chopped
2 tablespoons butter
2 cups shredded Cheddar cheese
3 cups milk
2 cups chopped broccoli, cooked and drained

In a large pot, sauté onion in the butter. Reduce heat to medium low, and add soup to pot and stir. Add cheese and stir until thoroughly melted. Whisk in milk until smooth. Add the broccoli and stir. Simmer for another 5 minutes, stirring constantly.