Preheat broiler on high.
Lay flank steak on a cutting board and cover with wax paper. Use a meat mallet to pound thin. (You want it no bigger than 1/2 inch.) Let steak come to room temperature.
In a small bowl mix together the olive oil, shallots and garlic.
Season both sides of the flank steak with salt and pepper. Add the shallot mixture to one side of the flank steak and spread evenly across. Top it with the four pieces of cheese, then the baby spinach.
Starting with the bottom edge roll up the steak away from you. Secure with toothpicks, spacing them 1 inch apart. Use a sharp knife to cut the steak into 1 inch pieces.
Add the steak to a broiler pan. Place in the broiler for 4 minutes, flip then cook 4 minutes longer.
Let the steak rest for 10 minutes before serving.