In a small bowl, combine the ground meat, chopped green onion, minced garlic, grated ginger, soy sauce, sesame oil, cornstarch, salt, and pepper. Stir until mixture is evenly combined and slightly tacky when pressed. Chill in refrigerator for 10 minutes to firm up (easier to handle).

Wonton Wrappers & Assembly

Lay one wonton wrapper square on a clean work surface with a corner pointing toward you (diamond shape). Place about 1 teaspoon of filling (heaping) into the center of the wrapper. Dip your finger into the cold water and moisten the edges of the wrapper.

Fold the wrapper in half to form a triangle, pressing air out and sealing edges firmly. Then bring the two outer corners of the triangle together, overlapping them slightly and sealing with a dab of water so the wonton forms a little purse or butterfly shape. Repeat with remaining wrappers and filling—this recipe yields 6 filled wontons.

Place assembled wontons on a tray lined with parchment or a lightly floured surface; keep them covered with a damp paper towel so the wrappers do not dry out before frying.

Frying & Serving

Pour oil into a medium skillet or small pot to a depth of about 1 to 1.5 inches (enough to half- to fully-submerge wontons). Heat over medium-high until the oil reaches 350°F (175°C) or until a small piece of wrapper sizzles and browns within about 15–20 seconds.

Carefully add 2–3 wontons to the hot oil without crowding. Fry, turning occasionally with tongs, for 1.5–2.5 minutes total until golden brown and crisp on all sides. Adjust heat as necessary to maintain 325–350°F (if you don't have a thermometer, aim for a steady moderate bubble and not smoking oil).

Using a slotted spoon or tongs, transfer fried wontons to a paper towel–lined plate to drain. Repeat with remaining wontons.

Serve hot with sweet chili sauce or soy-vinegar dipping sauce. Leftover fried wontons can be kept in a single layer on a wire rack in a 200°F (95°C) oven for up to 20 minutes to stay crisp before serving.