2 tbsp. tarragon vinegar
1/2 tsp. dried tarragon
1/2 c. mayonnaise
1 egg yolk
Salt & pepper to taste

Combine vinegar, tarragon, mayo and egg yolk in top of double boiler. Place over hot not boiling water. Beat with a whisk until mixture has thickened and is warm. Correct seasoning to taste with salt and pepper. Serve over steak. Makes 3/4 cup.