Preheat a grill pan or large cast-iron griddle or skillet to medium-high. Position a rack-lined baking sheet in the oven and preheat to 425 degrees . Cut horizontally through the middle of the steak, but not all the way through the meat, to make a deep slit; spread the steak open like a book.
Top the meat with the spinach, feta and olives (or sun-dried tomatoes), if using; season with pepper. Tightly roll up the meat into a long, thin log and tie with kitchen string to secure. Season the meat with salt and more pepper and drizzle with EVOO. Add the steak to the hot grill pan and grill all over, 5 to 6 minutes. Transfer the steak to the prepared rack in the oven and cook for 10 to 12 minutes more for medium-rare. Let the meat rest for about 5 minutes.
While the meat is cooking, in a saucepan, heat 1/4 cup EVOO, 4 turns of the pan, over medium-low heat. Add the garlic, chile and oregano and cook for a couple of minutes, then remove from the heat.
To serve, slice the steak into thin wheels and arrange on plates. Top with the garlic oil and serve with the warm bread.