Rooby's Cream of Broccoli Soup

Yield:	16 Servings
Categories:	Soups, Stews

3	tb	Butter
1	lg	Onion; chopped
5		Stalks celery; chopped
1	qt	Chicken stock
3	lb	Broccoli florets
24	oz	Evaporated milk; (2 cans)
1	c	Grated cheddar cheese; or to taste
3	tb	Flour
		Salt; to taste
		Fresh ground black pepper; to taste