Combine all ingredients for the dumpling filling (except the dipping sauce) in large bowl, and mix until just combined. Cover, and transfer to the fridge while you make the wrappers.
Add flour, xanthan gum, and salt in a bowl and stir together.
Add oil and hot water and stir with a wooden spoon until combined. You can add more water until a workable dough is formed.
Knead with your hands for about 5 minutes until smooth and soft. The dough will get smoother as you keep kneading. Wrap in a plastic cling wrap to prevent from drying while you work.
Take a small piece of the dough and roll into a 1-inch wide ball. On a lightly floured surface, use a rolling pin to roll out into a thin circle, about 1-2 mm thick and 3.5-4 inches in diameter.
You can fill the wrapper right away with the filling, but I prefer to make all the wrappers first before filling them. For the latter, lightly coat the wrappers in flour to keep them from sticking and stack them in a resealable plastic bag to keep them from drying. You can freeze them this way if you aren't filling the dumplings right away.
To fill the dumplings, have a small bowl of water ready and place a wrapper on your non-dominant hand. Use the other hand to add about 1½ tbsp of the filling to the center of the wrapper. Do not overfill. Dip your finger in the water, and moisten the outer edge of the top half of the wrapper.
Fold the wrapper in half and pinch the edges together to close. I like to crimp the edges with my fingers.
Place the dumplings on a baking sheet and cover with a plastic cling wrap as you work to keep them from drying out. Cook right away or freeze (see notes for how to freeze).
To steam: Fill a pot with 1 inch of water, and line the inside of a bamboo steamer or steamer rack with parchment paper, a cheesecloth, or napa cabbage leaves. Boil the water over high heat, then reduce to medium. Add the dumplings in a single layer and make sure leave some space between them - dumplings will expand as they cook. Steam for 7-8 minutes (or 12-15 minutes if frozen) until cooked through.
To fry: Heat a thin layer of oil in a non-stick skillet over medium heat until shimmering. Add the dumplings in a single layer and cook for 1-2 minutes until the bottoms begin to brown. Add 1/4 cup water and cover for 4-5 minutes (8-9 minutes for frozen dumplings) until the dumplings are cooked through. Uncover and let the dumplings cook until all the water has evaportated.
Enjoy hot, dipped in or drizzled with dipping sauce.