From America's Test Kitchen Season 9: Backyard Steak and Potatoes
Grilled potatoes are a summer classic, but we wanted to put a new spin on our grilled potatoes by adding rosemary and garlic for a heartier, more savory side. Unfortunately, we found it harder than it sounded to add garlic and rosemary flavors to plain grilled potatoes. Coating the potatoes with oil, garlic, and rosemary produced burnt, bitter garlic and charred rosemary. If we tossed the potatoes in garlic oil after cooking, the raw garlic was too harsh. We wanted potent garlic and rosemary flavors in our potatoes, without bitterness and charring. We learned that we needed to introduce the potatoes to the garlic-oil mixture not once, but three times. Before cooking, we pierced the potatoes, skewered them, seasoned them with salt, brushed on a garlic-rosemary oil, and precooked them in the microwave. Then, before grilling, we brushed them again with the infused oil. After grilling, we tossed them with the garlic and rosemary oil yet again. We finally had it—tender grilled potatoes infused with the smoky flavor of the grill and enlivened with the bold flavors of garlic and rosemary.
This recipe allows you to grill an entree while the hot coals burn down in step 1. Once that item is done, start grilling the potatoes. This recipe works best with small potatoes that are about 1 1/2 inches in diameter. If using medium potatoes, 2 to 3 inches in diameter, cut potatoes into quarters. If potatoes are larger than 3 inches in diameter, cut each potato into eighths. Since potatoes are cooked in microwave, use wooden skewers.