From America's Test Kitchen
Grilled Cornish game hens provide an attractive, elegant alternative to grilled chicken. We wanted to develop a foolproof technique that would deliver smoky notes, really crisp skin, and juicy meat infused with great grilled flavor.
We found that by butterflying the birds we could keep all of the skin on one side, which meant it crisped more quickly when placed facing the coals. Butterflying also produced a uniformly thick bird, which promoted even cooking. We needed to secure the legs to the body to keep the skin from tearing, so we developed a special skewering procedure that stabilized the legs, made it easier to fit the birds on the cooking grate, and created a restaurant-worthy presentation. A seven-ingredient rub gave the hens a sweet and savory complexity and helped crisp the skin even further, giving it a rich mahogany hue. Our quick glaze of ketchup, brown sugar, and soy sauce provided the crowning touch.
If your hens weigh 1 1/2 to 2 pounds, cook 3 instead of 4, brine them for an extra 15 minutes, and extend the cooking time in step 5 by 10 to 15 minutes. Thaw frozen game hens in the refrigerator for 24 to 36 hours before brining. To add smoke flavor to the hens, use the optional wood chips.