2 tsp. Mustard Powder ¼ C. Water 2 Tbsp. Flour 2 Tbsp. Butter 2 tsp. Vinegar 1¼ C. Water (boiling) ½ tsp. Salt 1/8 tsp Black Pepper
Mix mustard flour with water. Melt butter and stir in flour. Add boiling water, stirring to keep mix smooth. Add vinegar, mustard slurry, salt, and pepper. Bring to boil. Yield 1½ C.