For the people that have tp grill everything: Watermelon & Peaches: Wedges, Not Steaks Watermelon for grilling should be cut into triangles with the rind attached, as steaks of watermelon tend to fall apart when flipped and turned with tongs on the grill. A mini watermelon (something under five pounds) provides the perfect amount of watermelon for four to six people. Heat grill to medium high. Brush peaches with oil and grill cut-side down, until soft, 4 to 5 minutes. Flip skin-side down and grill until almost falling apart, 4 to 6 minutes more. Serve with ice cream, a drizzle of honey, and a sprinkling of flaky sea salt.