Basic White Sauce

4 T butter, divided
2 T onion, chopped fine
4 T flour
1 1/2 C milk
1/2 C heavy cream or half and half
1/2 tsp. salt
1/2 tsp. pepper

In a saucepan over medium low heat, sauté the onion in 2 tablespoons of the butter until soft, about 5 minutes. Add the remaining butter to melt, then add the flour. Stir to combine until smooth and cook for 1 minute. Pour the milk and cream into a measuring cup and slowly pour into the butter and flour mixture. Add the salt and pepper. Stir constantly until thickened. Use this for casseroles, as a base for cheese sauce, etc.