Preheat oven to 350°F (180°C)
Combine all ingredients for meatballs and form balls of approx. 2 ounces each. Heat 3 tbsp (45 mL) of vegetable oil in heavy skillet. Brown meatballs in batches, adding more oil if needed. Once browned move to parchment-lined baking sheet. When all meatballs have been browned, bake for 15-18 minutes or until cooked through.
While meatballs are cooking prepare sauce. Place sesame oil in a heavy skillet over low heat; once warmed add chili flakes, garlic and ginger, and cook until garlic just begins to brown. Add rice wine vinegar, sweet Thai chili sauce, maple and chicken broth and bring to a boil. Meanwhile combine cornstarch and water to make slurry; once sauce has boiled, reduce to simmer and add in slurry, stirring until thick.
When the meatballs have cooked through, gently stir them into sauce and top with green onion and toasted sesame seeds.