Beef Tenderloin Sprinkle tenderloin evenly with salt and pepper. Stir together butter and next 3 ingredients Rub mixture evenly over tenderloin. Cover and chill 1 to 2 hours. Place in an aluminum foil-lined 15- x 10-inch jellyroll pan. Bake at 500° for 30 minutes or until a meat thermometer inserted into thickest portion registers 145° (medium-rare). Remove from oven, and let stand 15 minutes. Serve with avocado Bernaise Sauce. Grilled Portobello Mushrooms With avocado Bernaise Substitute 8 large portobello Mushrooms, stems removed, for Beef. Follow above directions with butter mixture; omit chilling.