Advice for the charred fruit-curious
The first time I was served grilled fruit, it seemed like a magic trick. Growing up, burgers, hot dogs, brats, and the occasional sad vegetable packet were as adventurous as we got, so this raw ingenuity blew my mind. First of all, he had he eschewed both propane and lighter fluid-sodden briquettes for hardwood lump charcoal ashed over in a chimney, which I'd never seen before. Next, he'd sliced and pitted a few peaches, oiled them, and set them face-down over the still-warm embers of fire while we were still eating dinner, and he closed the lid. By the time we ready for dessert, he lifted them out, plopped each soft, char-streaked peach half into a bowl, scooped some vanilla ice cream on top, and for a coup de grace, ground fresh black pepper over it all.
Of course I had to replicate this party trick immediately, and naturally, I fouled it up the first few times. I had the heat too high or too low, I left the lid open, I didn't oil the grill enough, I tried to grill watermelon. (Seriously, it's mostly water and it burns in about three seconds if you're not careful.) But grilling fruit is something of a forte of mine now, and I've got a few bits of advice that will make it all a little simpler.
Patience is key. The particular joy of grilled fruit comes from the caramelization of the sugars, and that takes time. While it might seem like a great idea to just toss slices on alongside the protein, you'll just end up with hot, charred fruit. For larger, heftier fruit, wait until after you've pulled the mains and sides off the fire, thoroughly oil the grate, and place the halves, slices, and skewered (make sure to soak those skewers) chunks over the slightly cooler coals, or a flame that's been lowered to medium-high, between 350°F and 450°F. Then close the lid. The all-over heat will allow those gorgeous flavors to develop while the face-down side can pick up some slow sear from the metal. For particularly thick fruit, like peaches, plums, pineapple, sturdy melon, and apples, flip it over after a few minutes to make sure that the fruit gets cooked without burning on one side.
Use the top rack. If you're working with more delicate slices, cherries, or berries, move the whole operation to the top rack if you have one, or in a perforated grill basket or sheet—even a foil pouch or boat if that's how you're rolling. The lid still goes down, but you'll need to check more frequently.
Give it a booze bath. The natural sweetness of this fruit is fantastic on its own, but you can always add a little more fun. A little bath in rum or bourbon, or a splash of vanilla or balsamic vinegar can add depth and delight to all kinds of fruit. Brown sugar, maple syrup, or honey might seem like overkill, but it's probably not—so long as you keep an eye out to make sure it doesn't burn.
Drink your grilled fruit. If you've got an afternoon to spare and you're smoking a pork shoulder or a brisket anyhow, toss in a foil pan of cherries or halved lemons on the top rack or away from the heat and flip them after about 30 minutes. Keep checking them until the fruit is softened and soaked with smoke, and plop those in your drinks until they're gone—which won't be long.
Yes, bananas too. And if there's a banana on hand, slit the inner curve lengthwise, gently score the flesh of the banana, and pour in as much rum or vanilla as you find reasonable. Sprinkle in a little brown sugar, and close the slit. On the top rack or away from the heat, balance the banana on its back as best you can—skewer a few of them together or place a pan or foil-wrapped brick on either side to balance it—and let it cook until the insides are browned and heavenly. Scoop it onto ice cream, or straight into a dish.