1. Prepare the Chicken: Start by cutting the boneless, skinless chicken breasts into 1-inch bite-sized pieces. Pat them dry thoroughly with paper towels. This step is crucial for getting a nice sear on the chicken. Season the chicken pieces lightly with salt and black pepper.

2. Sear the Chicken: Heat the olive oil in a large skillet over medium-high heat. Once the oil is shimmering, add the chicken pieces in a single layer, making sure not to overcrowd the pan. You might need to do this in two batches. Cook for 3-4 minutes per side, or until the chicken is golden brown and cooked through. Remove the cooked chicken from the skillet and set it aside on a plate.

3. Whisk the Sauce Ingredients: While the chicken is cooking or resting, prepare the honey garlic sauce. In a small bowl, whisk together the honey, soy sauce, minced garlic, apple cider vinegar, and red pepper flakes (if using). In a separate small cup, dissolve the cornstarch in the water to create a slurry.

4. Simmer the Sauce: Reduce the heat to medium-low. Pour the honey garlic sauce mixture into the same skillet you used for the chicken. Bring it to a gentle simmer, scraping up any browned bits from the bottom of the pan. These bits add extra flavor to your sauce.

5. Thicken the Sauce: Slowly pour the cornstarch slurry into the simmering sauce, whisking constantly. Continue to whisk and cook for 1-2 minutes, or until the sauce has thickened to your desired consistency. It should be thick enough to coat the back of a spoon.

6. Combine Chicken and Sauce: Return the cooked chicken pieces to the skillet with the thickened honey garlic sauce. Toss gently to ensure all the chicken bites are thoroughly coated in the delicious sauce.

7. Final Touches and Serving: Cook for another 1-2 minutes, allowing the chicken to warm through and absorb more of the sauce’s flavor. Remove from heat and garnish with fresh chopped parsley or green onions, if desired, before serving immediately.