Oven Roast Beef Stuffed with Mushroom Barley Risotto

To Make Risotto

Cook mushrooms in 2 batches in large skillet. Heat 1 tbsp EACH oil and butter, over medium-high heat; add half the garlic and half of mushrooms. Season with salt and pepper and sauté until mushrooms are golden brown and tender, about 6 minutes; remove from pan. Cook remaining mushrooms with 1 tbsp. EACH oil and butter. Toss cooked mushrooms together with parsley; set aside.
Heat broth in microwave-safe measuring cup or bowl until hot, about 4 minutes on high. Cover and set aside.
Heat 2 tbsp of olive oil over medium-high heat in heavy medium saucepan. Add onion and remaining garlic; cook, stirring until aromatic and softened, about 3 minutes. Add barley and cook, stirring to coat with oil. Stir in wine and cook, stirring until wine is almost completely evaporated, about 3 minutes. Stir in ½ cup of the hot broth; continue stirring until stock has been absorbed, about 4 minutes. Reduce heat to medium and continue adding hot broth, ½ cup at a time until broth has been absorbed and barley is tender, about 30 minutes.
Stir in cream and cheese, stirring until creamy. Remove from heat; stir in reserved cooked mushrooms; set aside and let cool.

To Make Roast Tenderloin

Cut beef tenderloin down the centre, lengthwise, stopping when you are about ½ inch from the bottom of the roast. Open the roast like a book. Season inside surface lightly with salt and pepper. Spoon 2 cups of risotto down the centre of the tenderloin. Top with sprig of fresh rosemary. Bring 2 sides of tenderloin up and around the filling to meet. Use wooden skewers to join the meat together, spacing the skewers apart at 2-inch intervals. Use butcher twine to “lace up” the roast by weaving between the skewers (like lacing a shoe). Place the tenderloin on a rack in a shallow pan. Stick thermometer into the beef in the exposed beef around the risotto.
Rub beef with 1 tbsp oil and season lightly with salt and pepper. Oven-sear in 450°F oven for 10 minutes.
Reduce heat to 275°F oven and cook until meat thermometer reaches 140°F (60°C) for medium-rare, about 40 minutes. Remove from oven, cover loosely with foil and let stand for 10 minutes before carving into thick slices to serve.
Make ahead time: Risotto can be prepared ahead, once cooked, cover and refrigerate for up to 3 days.