Preheat smoker. Set your smoker to 225 degrees F.
Season roast. In a small bowl, combine the garlic, thyme, salt, pepper, and olive oil for the wet rub. Spread the rub on all sides of the trimmed tenderloin roast. Place the roast on the smoker and cook for approximately 1 hour, or until the internal temperature of the roast reads 115 degrees F if you want to finish with a rare roast. For medium rare, take the temperature up to 125 degrees F for this step.
1 Tablespoon olive oil, 3 cloves garlic, 2 teaspoons coarse Kosher salt, 2 teaspoons black pepper, 2 teaspoons fresh thyme leaves, 1 1 1/2-2 pound beef tenderloin roast
Prepare gravy. While the tenderloin is smoking, prepare the white wine mushroom gravy. In a large saute pan over medium heat, melt the butter. Stir in the shallots and cook until translucent, about 3-4 minutes. Carefully stir in the mushrooms and cook, stirring often, until the mushrooms are darker in color and soft, about 5 more minutes. Dump in the flour and stir until well combined.
4 Tablespoons salted butter, 1 shallot, 8 oz baby portobello mushrooms, 2 Tablespoons all-purpose flour, 1 cup white wine
Add remaining ingredients. Pour the white wine over the mushrooms and stir vigorously, scraping the bottom of the pan to loosen any cooked on browned bits. Stir in the beef stock and heavy cream. Season with the salt, pepper, and fresh thyme. Set aside, but keep warm.
1 cup beef stock, 1/4 cup heavy cream, 1 teaspoon fresh thyme leaves, salt and pepper
Sear steaks. Once your tenderloin has reached your desired temperature from the first step, remove the roast to a cutting board and allow to rest. Preheat either your grill, or a cast iron skillet with 1 Tablespoon olive oil, to high heat. Sear the tenderloin on all sides to form a nice exterior crust. This should only take 1-2 minutes per side. This final step will bring your tenderloin up to your desired doneness, 125 degrees F for rare of 135 degrees F for medium rare.
1 Tablespoon olive oil
Rest. slice, and serve. Transfer to a cutting board, rest for an additional 5 minutes, then slice into 3/4 inch thick medallions. Serve topped with the warm white wine mushroom gravy and fresh thyme leaves.