Prepare the Filling: Use a mortar and pestle or food processor to finely pound garlic, coriander roots, and black peppercorns into a paste. In a skillet over medium heat, add a splash of cooking oil and your spice paste, cooking until fragrant. Then, toss in chopped shiitake mushrooms and sauté until softened. Finally, add ground chicken and cook until just done, then add chopped vegetables, oyster sauce, soy sauce, and sesame oil, cooking until vegetables soften slightly.

Fold Rice Paper Dumplings: Cut the rice paper sheets in half, quickly dip each half in hot water for a few seconds, then lay them on a clean, dry surface. Stack two halves together, place a spoonful of filling in the center, fold to form a triangle, and press edges to seal.

Pan-Fry: Heat cooking oil in a pan until shimmering. Place prepared dumplings in the pan, frying for 3-4 minutes on each side or until golden brown and crispy. Flip carefully.

Serve Hot: Once done frying, remove dumplings from the pan and place on a plate lined with paper towels. Serve hot with dipping sauces.