"Picking up" on driven shoots as I do I get offered a lot of pheasants during the season; we have game of some sort on the table two or three times a week.
Hanging for a few days in a cool place does tenderise the meat and add flavour but it's more applicable to birds for roasting than other methods, however they all need to be hanged long enough for rigor mortis to disappear.
The fastest easiest and possibly the best recipe we use is...
Take the skinned breasts, cut a pouch into them sideways and push in a big teaspoon of pesto. Wrap in dry cured smoked bacon, and place in a shallow dish. Add enough dry cider to half cover them, cover with a lid or tight tinfoil and poach at 200 C for about 30 minutes. Drain off the cider reduce it to 1/3 original volume and when off the boil stir in a generous splodge of cream (creme fraiche is even better, particularly with a jolt of Calvados) to form the sauce. Briefly brown the bacon, place the breasts on your best mashed potato, and pour on the sauce. Sprinkle over with pine nuts and serve piping hot with peas and/or beans.
regards
eug