Set grill flame to high, and allow to preheat.
Add sun-dried tomatoes to a large bowl and cover with boiling water.. Allow the tomatoes to steep until they become soft (10 minutes). Once softened, drain tomatoes in a colander and chop.
Sandwich the steak between two pieces of plastic wrap. Using a meat mallet, pound meat until it is 1/4-inch thick.
Coat one side of the steak with garlic. Spread a 3-inch wide strip of cheese lengthwise down the center of the steak. Top cheese strip with the tomatoes and spinach. Roll the steak up tightly around the cheese and vegetable mixture. At the overlapping edges, use 8 skewers to hold the roll together. Sprinkle salt and pepper over the steak roll.
Slice the roll into portions that are approximately 1 inch thick, making sure that each piece has a skewer.
Coat the grill rack with oil. To cook the meat medium-rare, grill each portion of the pinwheels for 3-4 minutes per side. Flip the pinwheels with a spatula to prevent filling from falling out.
After grilling, allow the pinwheels to rest for 5 minutes. Remove the skewers, and serve.
