Place the flank steak so that the grain is going from right to left
Start by squaring the flank steak and removing any hard fat deposits
Then, with a really sharp knife, butterfly the flank steak. Cut parallel to the cutting board and leaving an inch or so not cut, you should be cutting along the grain
Then open the flank steak, using the knife to finish the cut so there is ½ an inch or so connected
Lay the butterflied flank steak flat, the grain at this point should be facing up and down the cutting board, this is a rotation from the start
Season both sides with Italian seasoning
Spread the mozzarella cheese out over the meat, leave one inch on one side for wrapping
Laydown a layer or two of spinach
Roll the flank steak, making sure to keep it tight and rolling with the grain
Cut six pieces of cooking twine and tie off 6 evenly spaced sections
Using a sharp knife, carefully cut the pinwheels by cutting in between the twine pieces
Place in a pyrex baking dish over a layer of spinach
Cook for 25 minutes or until the meat reaches the desired doness
Broil for 3 minutes or until the mozzarella is bubbly