An aromatic dish for small gatherings. These can be prepared on a sheet pan, but small skillets make a better presentation. Preheat oven to 400. Rinse hen, pat dry, and remove wing tips and backbone. Use scissors. Turn breast side up, open like a book, and whack it a time or two with your fist to crack the breastbone and flatten. Oil hen, season with salt and plenty of good black pepper. Line a well-oiled skillet with minced garlic and rosemary springs, place the bird on top, tuck the wings under the breast, and bake until nicely browned.