Beef tenderloin gets nice and tender in the oven while you make a delicious mushroom blend with garlic and butter.
Pat beef dry with paper towels. Let stand at room temperature 30 minutes. Position rack in center of oven, and preheat oven to 425°F. Season beef on all sides with 2 tsp. each kosher salt and pepper.
In an extra-large ovenproof skillet heat canola oil over medium-high. Add beef and cook 8 to 10 minutes, turning to brown on all sides. Transfer skillet to oven and roast 30 to 35 minutes or until medium-rare (135°F). Transfer beef to a platter; cover loosely with foil while preparing mushrooms.
Add 1 Tbsp. of the butter and the olive oil to same skillet. Add mushrooms and a pinch of kosher salt. Cook over medium-high heat, stirring occasionally, 6 to 8 minutes or until mushrooms begin to brown. Add shallots; cook and stir 2 minutes. Add garlic; cook and stir 30 seconds. Carefully add sherry; cook and stir 1 minute or until almost evaporated. Season to tasted with salt and pepper.
Stir juices from beef into mushrooms with remaining 1 Tbsp. butter and the thyme. Slice beef and serve with mushrooms.