Step 1

Adjust the oven rack to the center position and preheat to 350°F.

Step 2

Remove any excess fat from the lamb, leaving a thin layer. Dry with paper towels. Season both sides generously with salt and pepper.

Step 3

In a large 12-inch skillet heat oil over medium-high heat. Once the oil is hot add lamb fat-side down, cook until both sides are browned about 3 to 4 minutes per side. Sear the bottoms and sides for 30 to 60 seconds until browned, 8 to 10 minutes total for searing all sides.

Step 4

Transfer skillet to the oven and roast lamb fat-side up, until the center of the meat reaches 120°F to 125°F for medium-rare about 10 to 20 minutes, and 130°F to 135°F for medium, about 20 to 30 minutes.

Step 5

Allow meat to rest for 10 minutes before slicing. Meanwhile, make the red wine mushroom sauce.

Step 6

In a medium skillet heat oil over medium heat. Add garlic and onions, saute for 30 seconds.

Step 7

Add mushrooms to the pan, saute until softened, 6 minutes.

Step 8

Add wine and chicken stock to the pan, turn heat to high. Simmer until liquid is reduced to ¾ cups.

Step 9

Turn off heat, whisk in butter and thyme. Taste sauce and season with salt and pepper as desired.

Step 10

Serve lamb with mushroom sauce and pair with Zinfandel red wine.