• Prep the Halloumi. Place the block of cheese on a paper towel and wrap it around it to pat it dry. Then cut it into 4 to 6 approximately ¼-inch slices, horizontally parallel to the top of the cheese. Now place the slices on another paper towel and pat them dry.
• Sauté the Halloumi. Heat a large non-stick skillet (about 12-inch), thinly coated with olive oil, over high heat. Once it's very hot, place the Halloumi slices in the pan. If you don’t hear a sizzling sound, it's not hot enough yet. Wait until it is. Cook on high for the first minute, and then reduce the heat to low-medium. Sauté until the bottoms are golden, about 2 minutes. Then flip them and brown the other side. This should only take a couple of minutes. Remove them from the pan and place them on a large plate to cool.
• Prep the watermelon. Before you work with the watermelon, clean the skin with a damp paper towel.

  Use a Chef's knife to cut a flat surface on each side of the watermelon, so it's more or less a square/rectangle. Stand it on one of its bases and cut about 10 approximately ¼ to ½-inch slices. Then trim any bits of skin off, and to get them about the size of the cheese slices. (Save scraps to eat!) Set aside on a plate or cutting board.

  (You will need twice as many watermelon slices as cheese slices. This could vary, depending on how think or thin the cheese is sliced.)
• Prep the mint. Finely chop the mint, add it to a small bowl and mix it with 2 tablespoons of olive oil and a few turns of freshly ground black pepper. Set aside.

Assembly

• Line a sheet pan with parchment paper and place the watermelon slices on top, being sure they're relatively evenly-sized, and more or less are the same size as the cheese slices.
• Spread about half of the mint mixture, divided evenly, on the top surfaces of the watermelon slices.
• Place a piece of cooled fried Halloumi on half of the slices, and spread each one with some of the remaining mint mixture.
• Add tomato slices, Kalamata olives, both, anything else you might want to try, or nothing.
• Close the sandwich, and place a toothpick through the top of each one with a mint leaf and serve.