Nacho Cheese Sauce - cooking recipe

Ingredients

4 tablespoons butter
1 large onion
4 tablespoons flour
2 cups milk
1 lb cheddar cheese

Preparation

Melt butter.
Saute onions until caramelized.
Add flour and cook for 2-3 minutes on medium heat.
Add milk and cheese and stir frequently until melted, about 15 minutes.