1 boneless pork tenderloin, about 1 pound
Salt and freshly ground black pepper
3 tablespoons butter, extra virgin olive oil, or a combination
¼ cup marsala or white wine
¼ cup cream
1 tablespoon lemon juice OR Dijon mustard
Chopped fresh parsley leaves for garnish, optional
Sprinkle meat with salt and pepper. Put a large skillet over medium-high heat; when heated, add 2 tablespoons butter and/or oil. When butter foam subsides or oil dimples, add meat (cut in half to fit pan, if necessary). Brown it well on all sides, for a total of 4 to 6 minutes. Turn off heat, remove meat from pan, and let it sit on a board. When skillet has cooled a bit, proceed.
Cut meat into 1-inch-thick slices. Once again turn heat to medium-high, add remaining butter and/or oil and, when it's hot, add pork slices to pan. Brown on each side, about 2 or 3 minutes each. Turn heat to low and remove meat to a warm platter.
Add marsala or wine to pan, turn heat to high, and cook, stirring and scraping, for a minute. Lower heat slightly, add cream and cook until slightly thickened. Stir in lemon juice or mustard, then taste and adjust seasoning. Serve meat with sauce spooned on top, garnished, if you like, with parsley.
Original recipe from here.