As Charles Phan explains in Vietnamese Home Cooking, Chinese cuisine has a strong influence in certain places in Vietnam like the port town Hoi An. There, much of the food is a mash-up of cultures (including even Japan), so serving fried wontons is not a major leap, cuisine-wise. Phan's fried wontons use the same filling as his wonton soup--mainly shrimp, pork, mushrooms, and chestnuts--but here they are sealed like ravioli (no tricky folding!) and fried in canola oil. The richness of the dumplings is balanced by serving them with a spicy tomato sauce spiked with fish sauce.