8 cloves garlic, minced
1 teaspoon crushed red pepper flakes
2 tablespoons whole black
1/2 cup chopped rosemary
1 cup extra-virgin olive oil
4 pounds beef fillet
1/4 cup kosher salt
Fleur de sel, to scatter over cooked beef
Combine garlic, pepper flakes, black pepper, rosemary, and oil in a Ziploc bag, add the beef, and marinate in the refrigerator for 24 hours.
Preheat the oven to 500 degrees. Remove the beef from the marinade, rub with salt, and place on a half sheet pan.
Roast for about 30 minutes, or until the internal temperature reaches 120 degrees for medium rare. Remove from the oven and allow to rest for 15 minutes. Serve hot or at room temperature.