Cut the watermelon in half lengthwise. Place flat side down, and cut 1 ½ inch wide slice. Cut the largest rectangle possible from each of these slices. You should be able to get about 6 steaks from ½ of a watermelon.
Pat each of the steaks dry with paper towels. If you have time, place them in the refrigerator uncovered for 1 to 2 hours to dry out excess moisture. Give them a final pat right before preparing.
Whisk together oil liquid smoke, garlic, salt, pepper soy sauce and thyme. Pour the marinade onto your watermelon steaks making sure they are nicely covered and leave them in the fridge to marinade for at least 30 minutes, the longer the better.
Lightly grease a large saute pan over low/medium. Gently slide each steak in, cooking for about 5 minutes on each side. Increase heat to medium-high and continue to cook each side for one minute, or until lightly browned.
Serve warm, topped with the remaining of the marinade leftover from the curing.
Notes
store the remaining cooled steaks in the fridge for up to 2 days.