Heat vegetable oil in a wok over medium heat.
Add onion and sauté until translucent. Add garlic and cook until fragrant.
Add chopped mushrooms, mushroom seasoning (if using) and minced ginger. Cook until the mushrooms release their moisture and their liquid cooks off.
Remove from heat and allow mixture to cool slightly.
Place a teaspoon of mushroom filling in the center of a wonton wrapper.
Dip your finger in water and moisten the edges of the wonton wrapper with water.
Fold wonton in half to form a triangle shape, pressing out excess air and sealing the filling inside the wonton wrapper.
Bring the two bottom corners of the wrapper together and pinch them together to form a pillow shape.
Set aside on a large platter while you fill remaining wonton wrappers with the mushroom filling.
Heat about 1½-2 inches of vegetable oil in a wok over medium high heat.
Once oil is hot, add 3-4 wontons at a time to the oil and fry until golden brown and crisp.
Drain on a paper towel lined platter.
Serve hot with dipping sauces.