In a large bowl, toss potatoes in 2 teaspoons sesame oil. Season with salt and pepper. Add to air-fryer and cook at 400-degrees for 10-15 minutes, or until fork-tender.
While potatoes are cooking, heat remaining sesame oil in large skillet over medium heat. Add garlic and cook, stirring occasionally until fragrant, about 30 seconds. Add soy sauce, brown sugar, ketchup, vinegar and sriracha (if using), and cook until warmed through, about 1 minute. Remove from heat and stir in half the green onions.
Add cooked potatoes and toss in sauce until coated. Garnish with remaining green onions and sesame seeds. Serve and enjoy.
Substitute honey for brown sugar for a naturally sweetened twist!