Step 1

Rinse the Cornish hens under cool water, including the cavity. Pat dry with paper towels, set aside.

Step 2

In a large bowl, whisk together the buttermilk, salt, cayenne pepper, garlic powder, cumin and lime juice. Place the hens breast side down and cover with plastic wrap. Place in the refrigerator. Let the hens brine for at least 3 hours, or overnight.

Step 3

Preheat the oven to 425°F. Take the hens out of the brine and lightly pat dry with paper towels. Season the cavities with a little salt and pepper, and insert half a lemon and a sprig of thyme. Tie the legs together with kitchen twine. Brush the hens with melted butter, and season generously with salt and pepper. Place in a roasting pan. If you wish, you can surround the hens with red potatoes, brushed with butter and seasoned with salt and pepper.

Step 4

Place in the middle rack of the oven. Roast the hens for 50 minutes to 1 hour; until the skin is bronzed and the internal temperature in thickest part of the thigh is about 180°F.