Cut root ends off of pearl onions. Bring a pot of water to a boil, add pearl onions and blanch for 30 seconds to 1 minute. Drain and instantly plunge pearl onions into an ice bath (a bowl filled with cold water and ice cubes). Squeeze the ends of the pearl onions, and they should slip right out of the skin. Trim ends and set aside.
Mix flour, paprika, salt and mace in a plastic bag. Add chicken and shake to coat.
Heat oil in a large skillet over medium-high heat. Add chicken and brown on all sides. Turn off heat. Add brandy and ignite. Once flames die out, remove chicken and set aside.
Re-heat skillet to medium heat. Add pearl onions and mushrooms to pan, fry until browned, about 5 mins. Remove and set aside.