01Place top pan of double broiler or heatproof bowl over simmering water.
02Whisk yogurt, lemon juice, egg yolks, mustard, salt, pepper and Tabasco together in top pan.
03Cook over simmering water, stirring constantly until sauce is thick enough to coat back of spoon. This will take approximately 6 to 8 minutes. (Sauce can be kept at room temperature for up to 1 hour; reheat gently in double boiler.)