Bring a large pot of water to boil. While waiting for the water to boil, rinse peppers, slice off tops, scoop out the seeds from the inside, and use a paring knife to carve out "jack-o'-lantern" faces.
Once water is boiling, put the peppers in and cook for 5 minutes until peppers are soft. Remove from water to cool.
In a saucepan, cook quinoa according to package directions.
In a separate wok, heat up oil and saute onions until caramelized.
Stir in frozen mixed vegetables, and heat until cooked through.
Mix in eggs and cook until scrambled.
Add in drained quinoa until all ingredients are evenly distributed.
In a separate bowl, whisk together all sauce ingredients, and mix into the quinoa to evenly coat.
Stuff Teriyaki Quinoa into the cooled peppers and enjoy!