In a medium mixing bowl, whisk together the low-sodium soy sauce, rice vinegar, ginger, garlic, brown sugar, and sesame oil. If desired, add red pepper flakes and mix in cornstarch.

Place the chicken thighs in a resealable bag or dish, pour the marinade over and refrigerate for 30 minutes to 4 hours.

In a bowl, whisk together soy sauce, chicken broth, honey, rice vinegar, ginger, and garlic for the sauce.

Mix cornstarch with a tablespoon of water until smooth to create a slurry.

Heat vegetable oil in a skillet over medium-high heat and swirl to coat.

Add marinated chicken and cook for 3-4 minutes per side until golden brown and the internal temperature reaches 165°F.

Pour the sauce mixture into the skillet and scrap the bottom to incorporate the browned bits.

Bring sauce to a gentle simmer for 2-3 minutes to thicken slightly.

Gradually add cornstarch slurry to the sauce while whisking, stirring until the desired thickness is reached.

Taste the sauce and adjust seasoning with soy sauce, honey, or red pepper flakes if needed.

Combine the cooked chicken with the sauce in the skillet, simmer for 1-2 minutes.

Garnish with sesame oil, green onions, and optional sesame seeds. Serve immediately over rice.