Preheat oven to 450°. Rub beef tenderloin with olive oil; season with salt and pepper. Roast 25 minutes or until meat thermometer registers 140° (medium-rare). Let stand 20 minutes; thinly slice. Combine mayonnaise and horseradish in small bowl. Slice baguette diagonally into 30 slices. Spread each piece with mayonnaise mixture; top with beef and a fresh pea shoot.