Preheat oven to 400 degrees. Line a baking sheet with foil and place a cooling rack on top of the foil.
Stir together flour, salt, and black pepper. Pat wings dry with paper towels. Brush with oil, then toss in the flour mixture and arrange in a single layer (not touching) on the cooling rack.
Bake for 15 minutes, then broil for 2-3 minutes until crispy. WATCH CLOSELY so they don't burn.
While chicken wings are baking, prepare the sauce by combing soy sauce, brown sugar, rice vinegar, sriracha, sesame oil, and garlic in a medium sauce pan. Bring to a boil, stir together cold water and corn starch until dissolved, then whisk corn starch slurry into the boiling sauce. Once thickened, remove from heat.
Toss wings in the sauce and garnish with chopped green onions and sesame seeds if desired before serving.
This recipe as written makes 1.5 pounds chicken wings - for me this was about 16 wings. At 2-4 wings each, this would serve 4-6 people as an appetizer.