1 tbsp. butter
1 tbsp. flour
1 c. milk
3 tbsp. mayonnaise
2 tbsp. prepared mustard (yellow butter)
1 tbsp. lemon juice
1/4 tsp. salt
Dash of pepper

Top of double boiler over boiling water, melt butter. Add flour to make smooth paste. Add milk, gradually, stirring constantly until thickened. Add mayonnaise, mustard and lemon juice. Stir until thickened and warm. Season with salt and pepper. Will keep indefinitely in refrigerator and in freezer forever. Always heat over hot water.