1. In a large skillet over medium-low heat, cook onions in 3 tablespoons butter for 5 minutes or until tender.
2. Add sugar; cook over low heat for 30-40 minutes longer or until onions are golden brown, stirring frequently.
3. Meanwhile, rub oil over tenderloin.
4. Combine the pepper, garlic and salt; rub over beef.
5. In a large skillet, brown beef on all sides. Transfer to a baking sheet.
6. Bake at 425 degrees for 20-25 minutes or until meat reaches desired doneness. Let stand for 10 minutes.
7. In a small mixing bowl, beat horseradish and remaining butter until blended. Spread over bread slices. Place on baking sheet.
8. Broil 3-4 inches from heat for 2-3 minutes or until lightly golden brown.
9. Thinly slice the beef; place on toasted bread. Top with caramelized onions.
The poinsettia, a traditional Christmas flower, originally grew in Mexico, where it is also known as the ‘Flower of the Holy Night’. Joel Poinsett first brought it to America in 1829.