
Americans eat raw lettuce,it's put in salads, as part of a bigger meal or put in sandwiches. However, in China, lettuce is always cooked in dishes! It would be strange to eat raw vegetables unless they're part of a cold salad appetizer, even in that case, they're usually limited to tomatoes and cucumbers.
This dish is really good, you should try it. It's simple to make too, simply put together small slices of lettuce and tomato chunks, just like how you would prepare a salad. Then put the prepared vegetables in the frying pan, pour in some vinegar and a tiny bit of sugar. Stir the vegetables until they're done.