- With the rack in the middle position, preheat the oven to 180 °C (350 °F).
- In a saucepan, bring the maple syrup, broth, beet, and Worcestershire sauce to a boil. Reduce by half, about 10 minutes.
- Sprinkle the coriander over the tenderloins. Season with salt and pepper.
- In an ovenproof skillet, brown the meat in the butter. Add the sauce and bake for 16 to 18 minutes. Remove the skillet from the oven. Place the tenderloins on a plate and cover with aluminum foil. Reduce the sauce back over high heat until very syrupy. For a beautiful presentation of whole fillets, put the fillets in the pan after the reduction and coat thoroughly.
- Thinly slice the meat and cover with the sauce.