Spinach Casserole

Yield:	4 Servings
Categories:	Casseroles

10	oz	Spinach, chopped (frozen or fresh)
2	tb	Butter (or margarine)
1	sm	Onion, chopped
		Yogurt, plain (between 1-2 C)
2	tb	Flour
		Cheddar or parmesan cheese (between 1-2 C), grated
		Salt
		Pepper