1 cup dry red wine (such as Cabernet Sauvignon or Merlot)
1/2 cup beef or venison stock
2 tablespoons shallots, finely minced
1 tablespoon butter, chilled and cut into small pieces
1 teaspoon fresh thyme leaves
1 bay leaf
Salt and freshly ground black pepper to taste
Instructions
1. Prepare and Sear the Venison
Pat the venison loin dry and season generously with salt and pepper.
Heat the olive oil in a large, oven-safe skillet (cast iron is ideal) over medium-high heat until shimmering.
Sear the venison loin on all sides until a deep brown crust forms, about 2-3 minutes per side.
Reduce the heat to medium-low, add the butter, rosemary sprigs, and smashed garlic to the skillet.
Baste the venison with the melted butter and aromatics for about 1 minute.
2. Finish Cooking
Transfer the skillet to a preheated oven at 375°F (190°C).
Roast for 6 to 10 minutes, or until the internal temperature reaches 125°F (52°C) for medium-rare.
Remove the venison from the skillet and place it on a cutting board. Cover loosely with foil and let it rest for 10 minutes. The internal temperature will rise a few degrees while resting.
3. Make the Red Wine Reduction
While the venison rests, pour off any excess fat from the skillet, leaving the browned bits (fond) in the pan.
Place the skillet over medium heat and add the minced shallots, cooking until softened, about 2 minutes.
Pour in the red wine and bring to a simmer, scraping up the browned bits from the bottom of the pan with a wooden spoon.
Add the beef or venison stock, thyme, and bay leaf. Continue to simmer until the sauce has reduced by about half and lightly coats the back of a spoon. This should take about 8-12 minutes.
Remove the bay leaf and whisk in the chilled butter, one piece at a time, to thicken and enrich the sauce. Season with salt and pepper to taste.
4. Slice and Serve
Slice the rested venison loin into 1/2-inch thick medallions.
Arrange the slices on a plate.
Drizzle the red wine reduction generously over the venison.
Serve immediately with your favorite side dishes, such as mashed potatoes or roasted root vegetables.