Whisk together shallots, wine and olive oil in a large baking dish. Add the steak and turn to coat. Cover and refrigerate for at least 4 hours or overnight.
Heat grill to high.
Remove the steak from the marinade and blot with paper towels. Lay on a flat surface, cut side up, and season with salt and pepper. Cover the surface with the prosciutto slices, then top with the cheese and a layer of basil leaves. Starting with the side facing you, tightly roll up the steak around the filling. Using kitchen string, tie the roll in 4 or 5 places.
Brush the outside of the steak with oil and season with salt and pepper. Grill the steak over high heat until browned all over, 8 to 10 minutes. Turn the steak 4 times as it cooks. Move the meat away from the direct heat and grill for 15 to 20 minutes, or until an instant-read thermometer registers 125 degrees F for medium-rare. Remove from the grill and let rest 5 minutes before slicing. Slice against the grain into 1/2-inch thick slices and drizzle with the Cabernet-Shallot Reduction.
2 teaspoons olive oil
3 shallots, finely chopped
1 bottle Cabernet wine
1 teaspoon black peppercorns
1 tablespoon honey
Heat oil in a large saucepan on the grates of the grill over high heat. Add the shallots and cook until soft. Add the wine and peppercorns, bring to a boil and cook until thickened and reduced to 1 cup. Strain the mixture into a bowl and season with salt, to taste, and honey.