Wash and dry the hearts of romaine and separate the leaves. Place the romaine cups around the edge of a platter and set aside.
Combine all the ingredients (excluding the romaine and peanuts) in a large, resealable plastic storage bag or glass bowl and refrigerate. Allow to marinate for 1 hour. To ensure proper cooking, remove your prepared ingredients from the refrigerator approximately 10 minutes prior to cooking to take the chill off the ingredients.
Preheat a 9-inch stir fry pan. When the rim of the pan is hot to the touch, add 1/3 of your ingredients and stir fry. When the meat has changed color and is fully cooked place the cooked food in the middle of the platter with the romaine. Continue with the remaining meat mixture. To serve, place some of the meat mixture into the romaine cups and sprinkle with chopped nuts.
Serves 4 as a hearty appetizer or 2 as a light, but filling meal.