To prepare the wings: To debone the chicken wings, cut around each joint. Gently pull down the meat and remove the bones. Repeat with all pieces. Season both sides of the wings with salt and white pepper.
To stuff the wings: Stuff each wing with one piece of asparagus and one piece of carrot. You can substitute with other vegetables if you prefer.
To make the teriyaki sauce: In a bowl, whisk together the water, soy sauce, sugar, mirin, and sake. Set aside.
To pan-sear the wings: In a pan over medium-high heat, add the cooking oil and the stuffed wings. Pan-fry until golden brown, about 2 minutes per side.
To simmer the wings: Lower the heat to medium-low. Pour in the sauce and cover with a lid. Simmer for 7 minutes. Flip the wings, cover again, and simmer for another 7 minutes, or until fully cooked.
To reduce the sauce and serve: Remove the lid, turn the heat to high, and reduce the sauce until thick and glossy. Make sure the internal temperature of the chicken reaches 165°F (74°C). Serve immediately with the teriyaki glaze.