Preheat your oven to 350°F/180°C. This ensures your hens will cook evenly and develop that sought-after crispy skin.
In a small bowl, combine all of the dry ingredients: garlic powder, dried oregano, dried basil, smoked paprika, chili powder, salt, and ground black pepper. Mix them well and set aside.
Grab your thawed Cornish hens and pat them dry with kitchen towels. This step is crucial for getting that crispy skin. You'll want to ensure they have no moisture on the surface.
Stuff each hen's cavity generously with pieces of onion, garlic, lemon, and a sprig of rosemary. This infusion of flavors will be absorbed as they roast.
Truss the legs using butcher twine, if you'd like. This helps maintain the shape of the birds and keeps those aromatics snug inside.
Tuck the wings behind the birds for a neat presentation. This also helps them cook evenly.
Drizzle half of the olive oil over each hen, ensuring they’re well-coated. This will create a beautiful, golden crust.
Now, generously season the hens with the dry rub you prepared earlier. Make sure to get it all over, even under the skin for maximum flavor.
Place the remaining onion, garlic cloves, lemon, and rosemary in a 9×13-inch roasting dish. This aromatic base will keep the hens elevated while adding depth to the dish.
Place the seasoned Cornish hens on top of the aromatics in the roasting dish. Drizzle the rest of the olive oil over them.
Add a splash of water or chicken stock to the pan. This will help keep everything moist and create a delicious sauce.
Roast uncovered in the oven for about 1 hour or until the internal temperature reaches 180°F/83°C. You want that skin to be golden and crispy.
Once cooked, carefully remove the hens to a plate, and tent with foil to rest. This step helps keep them juicy.
Pour the cooking juices into a small saucepan and reduce for about 5 minutes to create a sauce. Drizzle this over the hens when serving.
Finally, cut each Cornish hen in half and serve with sides like mashed potatoes, rice, or roasted/steamed vegetables. Drizzle some of that delicious sauce on top, and enjoy!