Clean and wash the Brussels sprouts and cook in boiling salted water for about 5 minutes. Remove and immediately rinse in ice water. Meanwhile peel onions and cut into strips. Peel ginger and cut into fine strips. Wash the meat and dab dry. Remove bones with a sharp knife. Cut meat into strips.
Heat oil in a large pan. Fry meat for about 4 minutes, turning once in between. Add onions, ginger and Brussels sprouts. Season with salt, sambal oelek, cinnamon and mace. Close the pan with a lid and braise over a low heat for about 4 minutes. Arrange in bowls