Brush each side of the cheese slice with water or run quickly under water. Then, dredge in the flour, shaking off excess flour.
Place cast iron skillet or heavy-bottomed skillet over medium-high heat until hot and then turn the heat to medium. Pour in the olive oil.
Add cheese to the hot pan and cook until the cheese just begins to melt and a golden brown crust forms, about 2 minutes. Quickly flip the cheese and cook another 1-2 minutes until golden brown on the other side.
Remove the skillet from the heat immediately and place on a wooden cutting board. You can skip this next step if you'd like and go right for adding garnish.Make sure you have alot of space above the pan as the flame can get quite high. Pour the bourbon or brandy over the cheese in the skillet and then light the bourbon using a long lighter so you can stand as far away from the pan for safety. Squeeze some lemon juice over top after the flames extinguish (you can gently blow on the flame to help it extinguish).
Serve cheese in the pan or on a plate, drizzled with honey and fresh thyme if desired.
Video
Notes
If you can't find Graviera cheese, here are a couple of other alternatives you can try: kasseri, halloumi, manchego or even paneer.