Make the Glaze: Add the honey, crushed red pepper and balsamic to a saucepan and bring to a simmer. Turn off the heat when the glaze coats the back of a spoon. Let it cool completely.
1/4 cup honey, 2 tsp crushed red pepper, 2 tbsp white balsamic vinegar
Cut the Watermelon: Cut the watermelon in half and remove the rind. Cut a rectangle about 1 inch thick, then slice it in half lengthwise into two rectangles about 1/2 inch thick. See the video for the cutting technique.
1 small watermelon
Cut the Feta: Cut the feta block to match the size of the watermelon rectangles. Slice it in half lengthwise into rectangles about 1/2 inch thick.
1 large block feta
Assemble: Place one watermelon rectangle down, top with the feta, then the second watermelon rectangle. Cut the stack into 6 squares. Repeat with the remaining watermelon and feta.
Finish: Top with the glaze, crushed pistachios and mint. Skewer each bite.