Make the dumpling dough: Whisk both flours in a bowl. Add oil and eggs and stir until dough forms. Transfer dough to a lightly floured work surface and knead until smooth, 4–6 minutes. Divide dough into 4 balls and wrap individually in plastic wrap. Chill for 1 hour.
Make the dumpling garnish: Heat oil in an 8″ skillet over medium and cook onion, stirring occas