In a medium bowl, stir together the ground chicken, scallions, garlic, ginger, soy sauce and sesame oil until well combined.
To assemble the potstickers, arrange the wonton wrappers on a work surface and fill a small bowl with water. Spoon about 2 teaspoons of the chicken mixture into the center of each wrapper. Dip your finger in the water then run it around the edges of each wonton wrapper. Fold the wrappers in half and pinch pleats along the top. Press the bottoms of the potstickers to create flat bottoms.
Add 2 tablespoons vegetable oil to a large sauté pan set over medium-high heat. Swirl the oil to coat the bottom of the pan, then add a portion of the potstickers in a single layer and sear the bottoms until they are golden brown and crunchy.
Once the potstickers are browned on the bottom, add 1/4 cup water to the pan and cover it immediately to steam the potstickers until the chicken is cooked through, about 5 minutes.
Remove the lid and continue cooking while swirling the potstickers in the pan until all of the water has evaporated.
Transfer the potstickers to a paper towel-lined plate then repeat the searing and steaming process with the remaining potstickers.