Preheat grill or broiler and put the red pepper over (or under) high heat. Char on all sides until fully blackened. Remove from heat and place in a bowl tightly covered with plastic wrap. Set aside for 30 minutes.
Peel the blackened skin from the pepper, it should come off easily due to the sealed resting time. Remove the stem, and cut the pepper open and remove the seeds on the inside. Place the pepper flesh on a paper towel to dry.
Mix the ricotta, parsley, and garlic in a bowl and season with salt and pepper. Dice the red pepper and add about 1/3 of a cup of the pepper to the mixture. (save the rest for another use) Cover and allow the mixture to cool.
Butterfly the flank steak - Place the flank steak on your work surface with the grain running perpendicular to you and the thinner side closest to you. Grab your sharpest knife. Place your hand flat on top of the steak and starting from the thinner end closest to you, cut the steak little by little so that it opens like a book with the hinge or spine of the book being the thicker edge of the steak furthest away from you. Season the meat with salt and pepper.
Spread the ricotta mixture in a thin layer over the entire “open book” of the steak.
Roll the steak up into a log starting with the edge closest to you so the mixture spirals through the meat. Season the outside with salt and pepper.
Allow the log to cool in the fridge for about 1 hour.
Press a skewer straight down through the center of the meat and repeat every inch the long way along the log. Repeat with two more rows of skewers, one on each side of the original row. Slice the meat into 1 inch slices so that 3 skewers are on each pinwheel. Place on to a tray and slide the meat so it is centered on the skewer. Once finished, return the tray to the fridge for another 30 minutes.
Preheat grill to medium high heat.
Brush the pinwheels with some oil to prevent sticking. Grill on medium high heat to brown on both sides and cook through. Remove from heat and allow to rest for 5 minutes before serving.