2. Cut tenderloin halfway through lengthwise; open out. Sandwich 24 grape halves together with 1/4 cup butter; arrange filled grapes down the center of 1 tenderloin. Place second tenderloin on top to form a roast; tie with string.

3. Place tenderloin roast in a shallow roasting pan. Arrange onion, carrot and bay leaf around roast; sprinkle with thyme. Pour wine and stock around roast. Roast in preheated oven for 1 1/4 hours or until done. Pork should reach an internal temperature of 170 degrees.

4. Move roast to a warm serving platter; cover with foil to keep warm. Remove fat from cooking liquid. Strain liquid into a medium saucepan.

5. Cream flour and butter to make beurre manie'; gradually whisk flour mixture into strained cooking liquid. Cook over low heat, stirring constantly until thickened. In a small bowl, beat egg yolk lightly; stir in some of hot sauce. Return mixture to saucepan; simmer sauce 2-3 minutes. Pour sauce over roast; garnish with remaining grape halves. Makes 4 servings.