Place shrimp in a bowl and add the garlic, coriander, fish or soy sauce, oyster sauce, brown sugar, and chili.
Toss well and set aside to marinate 10 minutes (or up to 30). Meanwhile, prepare your pan or wok for frying. A wok requires oil. Pour oil about 1 inch deep.
Toss the shrimp once again before wrapping. To wrap, lay out the first wonton wrapper on the diagonal (point facing towards you). Brush the entire surface with beaten egg, then position the shrimp horizontally across the center (with its tail sticking out past the left corner). Fold the right corner over the bottom of the shrimp, then bring up the bottom and tuck over. Roll quite tightly to finish and press firmly to seal.
Place wrapped shrimp on a plate lightly dusted with cornstartch (to keep wrappers from sticking).
Heat oil over medium-high heat. To test if oil is hot enough, dip one of the wrapped shrimp in – if it starts to sizzle and cook, the oil is ready. Fry the wrapped shrimp about 1 minute per side or until light golden brown and crunchy. Once your first batch is frying, reduce heat to medium. Drain on paper towels.
Serve immediately either as or with Thai sweet chili sauce for dipping. This appetizer can be kept in a warm oven (uncovered) for up to 1 hour.