In a large skillet over medium-high heat, add 2 tablespoons, about 2 turns of the pan, canola oil. Saut the Napa cabbage, carrots and scallions until tender, about 5 minutes. While it is cooking, in a small saucepan, mix together the sugar, rice wine vinegar, and soy sauce. Heat through, then pour onto the cabbage mixture, toss around, and turn off the heat.
Serve the Sweet and Sour slaw under the pot stickers.