Preheat oven to 375°F (190°C).
Lightly spray a standard 12-cup muffin tin with cooking spray.
Press one wonton wrapper into each muffin cup, pleating the edges to form a bowl shape.
Bake the wonton shells for 6 to 8 minutes or until the edges are golden brown and crispy. Remove from oven and set aside to cool.
Heat vegetable oil in a large skillet over medium-high heat. Add the diced chicken and cook for 5 to 7 minutes until cooked through and lightly browned.
Add the teriyaki sauce to the skillet and simmer for 2 to 3 minutes until the sauce has thickened and coated the chicken thoroughly.
In a separate bowl, toss the coleslaw mix with rice vinegar and sesame oil until evenly coated.
To assemble, place a small amount of the slaw mixture into each baked wonton shell.
Top the slaw with a spoonful of the teriyaki chicken.
Garnish with sliced green onions and toasted sesame seeds before serving.