Step 1: Butterfly the flank steak: Trim the edges of the flank steak so that they are straight and the meat is an even rectangle. Position the flank steak lengthwise along the edge of the cutting board. Using a very sharp, long, slender knife, make a horizontal cut through a long side, slicing the meat almost in half (stop about 1/2 inch from the opposite side). Open the flank steak up like a book, then pound the center flat with a meat pounder or the side of a cleaver. The idea is to create a piece of meat that’s 12 to 15 inches long and wide.

Step 2: Season the meat on both sides with salt and pepper. Arrange the butterflied flank steak cut side up on the work surface so that a short side is closest to you. Sprinkle the oregano over the meat.

Step 3: Arrange the slices of Provolone, prosciutto, salami, pepperoni, and mortadella, if using, in layers on top of the flank steak, placing them 1/2 inch from the bottom and sides of the meat. Leave the top 2 inches of the flank steak bare. Sprinkle the peppers, if using, on top. Starting with the edge of the flank steak closest to you, roll up the meat into a tight cylinder. Carefully move it to the side.

Step 4: Cut four 15-inch-long pieces of butcher’s string. Position the strings on the cutting board so that they are parallel to each other and roughly 2 inches apart. Place 1 slice of pancetta across the center of the strings so that it is perpendicular to them.

Step 5: Place the rolled-up meat on top of the slice of pancetta so that it is perpendicular to the strings. Place a slice of pancetta lengthwise on top of the rolled meat. Press the remaining 2 slices of pancetta against either side of the rolled flank steak. Tie the pieces of string together around the meat so that they hold the slices of pancetta tightly against it. The braciole can be prepared up to this stage several hours ahead and refrigerated, covered.

Step 6: When ready to cook, place the drip pan in the bottom of the rotisserie. Gently flatten the flank steak roll with your hand so that it will fit in the rotisserie basket, then place it in the basket so that the spit will pass through it crosswise. Close the basket tightly and attach it to the rotisserie spit. Attach the spit to the rotisserie, then turn on the motor. If your rotisserie has a temperature control, set it to 400°F. Cook the braciole until crusty and brown on the outside and cooked through. To test for doneness, use an instant-read meat thermometer: Insert it into the center of the braciole but not so that it touches the spit. The internal temperature should be about 190°F.

Step 7: Transfer the braciole to a cutting board and let cool for a few minutes. Remove and discard the strings. Cut the roll crosswise into 1/2-inch slices and serve. The braciole is also pretty tasty served at room temperature or even cold.