AA Choy is the leafy portion of celtuce or wo shun and is a common leafy green vegetable that is very popular in both Taiwan and China. Wo shun is the large edible stem portion of the plant when it matures and is usually sliced like a bamboo shoot and used in authentic pork with garlic sauce. AA choy is a refreshing leafy green that tastes a lot like romaine lettuce (not quite as crunchy) and is usually stir fried with fresh chopped garlic or blanched and served with an oyster sauce topping (similar to yu choy sum).