Begin the Marsala sauce by heating the olive oil in a large saute pan. Cook the shallots
) and mushrooms gently until they become translucent. Deglaze
the pan with the wine
and add the stock and fresh thyme. Allow to reduce by two-thirds.
Preheat the grill to medium-high heat and season meat on both sides with salt and pepper. Sear
the meat on both sides, and grill
to about 128 degrees F internal temperature for medium-rare. Remove meat from grill and let rest.
Marsala sauce and whisk
in butter to finish. Season with salt and pepper, as needed. Spoon the sauce
over the grilled steaks, garnish
with chopped chives, and serve.