Prepare Wine Marinade (see below). Place the butterflied flank steak in a large dish, pour the prepared marinade over the top, cover tightly, and refrigerate overnight or all day.
Place the whole bell peppers either over a flame or under the broiler of your stove until the skin is charred. Place in a bowl, cover with plastic wrap, and let steam for approximately 10 minutes. Peel the charred skin off the peppers, remove stem and seeds, and cut into large chunks.
When ready to finish preparing the flank steak, remove steak from the Wine Marinade. Scrap up the parsley leaves and garlic from the marinade and rub onto the flank steak.
Using a rubber spatula, spread the Spicy Chile Pepper Sauce over the surface of the flank steak. Place the bell pepper chunks on top of the pepper sauce, sprinkle parsley leaves over the top, then make a layer of prosciutto slices, and then spread the fresh basil leaves over the top.
Begin rolling up the flank steak with the edge closest to you and roll away from you (the steak should be rolled parallel to the grain so that once you cut into the steak, you are cutting against the grain).
Once rolled, tie the flank steak roll up with cooking string every 2 inches or so. Sprinkle the roll with salt and pepper.
Preheat barbecue grill. Place prepared flank steak rolls onto the hot grill. Cover barbecue with lid, open any vents and grilluntil steak is medium rare, for approximately 15 to 20 minutes, or until the internal temperature reaches desired temperatureon your meat thermometer. Turn the rolls every few minutes and baste with any leftover Wine Marinade. This steak is best cooked rare to medium rare.
Rare - 120 degrees F
Medium Rare - 125 degrees F
Once cooked, remove the flank steak rolls from the grill and place on a separate plate. Cover with aluminum foil and let rest for approximately 6 minutes before cutting. Remove the string and, using a very sharp knife, slice the flank steak into individual rolls.
NOTE: Your end pieces may not be perfect, so reserve those for a snack.
In a bowl, whisk the olive oil, vinegar, garlic, parsley, and pepper to together.
* Either have your butcher butterfly the flank steak or split the meat down the center so it lays flat and then break down the tough fibers by running it through his meat tenderizer. You can also tenderize the flank steak with a meat mallet.
Stuffed Flank Steak with Roasted Peppers Recipe: https://whatscookingamerica.net/karencalanchini/stuffedflanksteakpeppers.htm