Bring a medium pot of water to a boil. Add sweet potatoes and cook 12 to 15 minutes until very tender. Drain sweet potatoes in a colander. Return pan to medium heat. Add butter to the pan. When butter melts, add nuts and toast for 2 minutes. Add sugar and let it bubble. Add bourbon and cook out alcohol, 1 minute. Add orange juice and the cooked sweet potatoes. Smash with a masher and season the sweet potatoes with nutmeg, salt and pepper.