Use a sharp knife and cutting board to cut the watermelon into 1-inch thick slices, then brush both sides lightly with olive oil using a brush or spray.
Preheat the grill or grill pan over medium-high heat until hot, with visible heat waves and a slight smoky aroma.
Place the watermelon slices onto the grill, making sure there is even contact, and cook for 2-3 minutes until grill marks start to form and edges begin to char slightly.
Flip each slice using tongs and grill for an additional 2-3 minutes until the other side develops similar grill marks and a smoky aroma; the flesh should start softening slightly.
Remove the grilled watermelon slices from the grill and transfer to a serving platter; optionally sprinkle with salt and black pepper for seasoning.
Garnish with chopped fresh herbs like mint or basil leaves before serving for a fresh contrast to the smoky sweetness.
1 inch watermelon slices
