In a medium bowl, whisk together the soy sauce, honey, brown sugar, and rice wine vinegar until the sugar dissolves completely. This creates a balanced sweet and savory foundation. Add the minced garlic, grated ginger, crushed red pepper flakes, and toasted sesame oil, stirring well to combine all aromatics and spices evenly throughout the liquid.

Place the chicken breast chunks into a resealable bag or shallow container. Pour the marinade from Step 1 over the chicken, making sure all pieces are fully submerged and coated evenly. I like to massage the bag gently to distribute the marinade around every piece. Refrigerate for at least 30 minutes, or up to 24 hours for deeper flavor development—the longer the marinating time, the more pronounced the teriyaki flavor will be.

Remove the marinated chicken from the refrigerator and let it sit at room temperature for 5-10 minutes before cooking. Choose your cooking method: for grilling or pan-frying, heat your pan or grill to medium-high heat and cook the chicken pieces for 6-8 minutes per side until golden and cooked through (internal temperature of 165°F); for baking, arrange the chicken on a parchment-lined baking sheet and bake at 375°F for 20-30 minutes, stirring halfway through, until the internal temperature reaches 165°F.

Remove the cooked chicken from heat and let it rest for 5 minutes before serving. This brief resting period allows the juices to redistribute throughout the meat, keeping it tender and moist rather than releasing all the moisture when cut. Serve warm, optionally drizzling with any remaining marinade from the pan or container.