Cut and marinate the chicken: Cut boneless chicken thighs into bite-sized pieces. Season them with salt, black pepper, and cooking wine, then sprinkle in the corn starch and toss everything together until each piece is coated. This gives the chicken a light, crispy exterior when cooked.
Prepare the sauce: In a separate bowl, mix together soy sauce, mirin, sugar and water until well combined. Set aside — this tangy, sweet, and savory sauce will come together quickly once the chicken is in the pan.
Sear the chicken: Heat a pan over medium heat and add the chicken pieces. Sear them on one side until they turn golden brown, about 3 minutes. Then flip to cook the other side.
Add onions: Toss in the sliced onions and cook for 1–2 minutes until they soften slightly and start to sweeten.
Add the sauce and lemon: Pour the prepared sauce over the chicken and onions. Add the lemon slices to the pan and squeeze in fresh lemon juice for extra brightness. This creates a glossy, flavorful coating for the chicken.
Simmer briefly: Let everything simmer together for about a minute so the sauce thickens slightly and the flavors meld perfectly.
Serve: Spoon the chicken, sauce, and onions over a bowl of hot rice. Make sure each bite gets some of that tangy lemon sauce — it’s comforting, bright, and just the right amount of sweet and savory. Enjoy!