
Heat the olive oil in a large cast iron skillet over medium heat, until shimmering.
Once the oil is hot, add the chicken in a single layer. Sear for 2-3 minutes per side for cubes, or 4-6 minutes per side for whole chicken breasts, until browned and almost cooked through. The internal temperature should reach 155-160 degrees F (68-71 degrees C).
Meanwhile, whisk together all ingredients for the teriyaki sauce in a bowl.
Once the chicken is cooked, pour the teriyaki sauce over the chicken and reduce heat to medium low. Simmer for 5-7 minutes, until the sauce thickens and slightly reduces.
If desired, garnish with sesame seeds and green onions.