How to Make It
Preheat the oven to 400°. Using your fingertips, carefully loosen the breast skin of each hen; tuck the cilantro sprigs under the skin. Season the cavities with salt and pepper and tuck an orange quarter into each one. Set the hens on a baking sheet, rub them with 1 tablespoon of the olive oil and season with salt and pepper. Roast the hens for 60 to 70 minutes, or until the juices run clear when a thigh is pierced. Remove from the oven and preheat the broiler.
Meanwhile, in a medium skillet, toast the cumin seeds over moderate heat, shaking the pan occasionally, until fragrant, about 1 minute. Stir in the orange juice, honey, ginger preserves, cayenne and orange zest and cook until syrupy, about 4 minutes. Brush the glaze all over the Cornish hens.
Broil the hens for about 2 minutes, until browned all over. Transfer the hens to a serving platter and keep warm; reserve the pan juices.
In a large skillet, heat the remaining 3 tablespoons of olive oil until shimmering. Add the garlic and cook over moderate heat, stirring, until golden, about 3 minutes. Add the radicchio and cook, stirring, until wilted, about 3 minutes. Stir in any reserved pan juices, season the radicchio with salt and pepper and cook for 1 minute longer.
Spoon the radicchio onto plates, top with the hens and serve.