Instructions: To make beef: Preheat oven to 425 degrees.

Pat beef dry and cut 1/2 inch-deep slits at 1 inch intervals all over roast, then insert 1 piece of pancetta into each slit. Sprinkle beef with kosher salt and pepper. Heat oil in a 12 inch heavy skillet over high heat until just smoking, then brown beef on all sides, about 5 minutes per side.

Transfer beef to a small roasting pan. set skillet aside.

Roast beef in middle of oven until an instant-read thermometer inserted diagonally 2 inches into center registers 120 degrees F, about 25 minutes.

Transfer beef to a cutting board and let stand, loosely covered with foil. (Beef will continue to cook as it stands, reaching 130 degrees for medium-rare.)

To make sauce: Meanwhile, heat same skillet over moderately high heat until oil is hot but not smoking, then saute shallot until golden, about 2 minutes.

Add red wine and Marsala and deglaze skillet by boiling, stirring and scraping up brown bits, until liquid is reduced by about one third. Add demi-glace and jelly and briskly simmer, whisking, until jelly is incorporated, about 2 minutes. Add butter, 1 bit at time, whisking until incorporated, then remove from heat. Whisk in salt and pepper. Pour sauce through a fine sieve into a bowl, pressing on solids.

Pour sauce over roast and serve.

If you would like to email yourself the recipe for later use, or share the recipe with your friends or family, enter the email addresses below and this recipe will be emailed to you and others as well.