Brush the grill grates with a bit of oil and then preheat the grill or grill pan to medium heat.: You will notice a faint sizzle when the oil on the grates heats, and a clean, warm smell that hints at caramelization to come. This step helps minimize sticking and creates a consistent surface for even char marks. If the grates are not oiled, the fruit can cling and tear, so take a moment to wipe a bit of oil across the bars. A common mistake is overheating the pan before oiling, which can smoke excessively and burn the fruit, so aim for moderate heat rather than the highest setting.
Cut 4 medium Freestone peaches in half and remove the pit from the peaches using a melon baller or a small scoop. Lightly brush the cut side of the peaches with additional oil.: When you cut the peaches, you should see juicy flesh and a fragrant, almost floral aroma. Removing the pit carefully preserves the peach half so it sits flat on the grill, giving a broad contact area for those beautiful grill marks. Lightly brush the cut side with additional oil to encourage browning. If the peach is overly soft, handle it gently to avoid squishing, and if you find the pit sticking, rotating the fruit slightly while scooping usually helps.
Place the peaches on the grill, cut-side down for 4-5 minutes, until char marks form, and the peach begins to soften.: The scent of oil warming on the fruit is subtle but important, as it helps sugars on the surface brown rather than burn. Use a pastry brush or your fingertips to spread a thin, even layer. Too much oil can drip and flare, creating hot spots, so less is more here. One trap is to skip oiling and then force the peaches to stick when you try to flip them, so take the extra minute to coat them evenly.
Remove the peaches from the grill and serve warm as desired.: You will hear a gentle sizzle and soon see deep brown to black char lines appearing, which contrast with the glossy, slightly wrinkled flesh around them. The sugars are caramelizing, producing a warm, sweet aroma that fills the air. This short sear firms the outer flesh while making the interior tender and jammy. Do not press down on the peaches, or you will squeeze out the juices, and avoid leaving them too long or they will collapse into mush.
Remove the peaches from the grill and serve warm as desired: The aroma will be rich and fragrant, and the surface should be lightly blistered while the center remains tender. Serve immediately for best texture, because as they cool the juices settle and the fruit loses some of its warm silkiness. A typical error is letting them sit too long on a plate without covering, which can dry the surface slightly, so serve quickly or tent loosely to retain warmth.