Heat a nonstick pan on medium heat. Once hot. add the oil. Saute the ginger and garlic until light golden brown. Add in the cabbage and saute until wilted. Place in a bowl to cool for 5 minutes.
Add the ground turkey, scallions, soy sauce to the bowl and mix well.
Lay down the wonton wrappers on a dry, clean surface, brush lightly with water around the edges, and place a teaspoon of filling in the center.
Fold opposite sides toward the center.
Repeat with remaining sides.
Seal the corners by gently pressing them together.
Lightly grease a nonstick pan with nonstick spray. Fill the pan with about a 1/2 inch deep of water and place over medium heat and cover with a lid. Once bubbles start to form in the water place the dumplings in a single layer (in batches if needed being careful not to overcrowd the pan) and cover with a lid. Gently simmer to an internal temperature of 160°F using a thermometer.
Remove onto paper towels to drain any excess water.
For the sauce: whisk together all ingredients in a bowl. Place in a saucepan over medium low heat and stir until smooth and warm. Remove from the heat.
Spoon the sauce over the dumplings and serve. Garnish with scallions.