Preheat your grill to medium-high heat, around 400°F (200°C). Slice the watermelon into thick wedges, about 1 inch thick. Lightly oil the grill rack to prevent sticking.

Grill the watermelon for 5-6 minutes on each side until nice grill marks appear and it starts to caramelize slightly.

Remove the watermelon from the grill and allow it to cool for a few minutes at room temperature before chilling in the refrigerator for about 15-20 minutes.

Layer the cold watermelon wedges on a serving platter, then sprinkle the heirloom cherry tomatoes, arugula, and blueberries on top.

Crumble feta cheese over the pizza and scatter Greek olives if desired. Adjust toppings as per your taste.

Drizzle olive oil over the entire Watermelon Pizza, then sprinkle with kosher salt and coarsely ground pepper. Finish with balsamic glaze if preferred before serving.