Step 1: In a medium bowl, whisk together the pineapple juice, soy sauce, brown sugar, and ketchup until the sugar is fully dissolved.
Step 2: Add the rice vinegar, grated ginger, minced garlic, and sesame oil to the mixture. Stir well to combine all the aromatic flavors into the easy huli huli chicken sauce.
Step 3: If using as a marinade, pour 1 cup of the sauce over your chicken pieces in a zip-top bag and refrigerate for at least 2 hours (or overnight).
Step 4: Reserve the remaining easy huli huli chicken sauce in a separate container for basting or dipping.
Step 5: To thicken for use as a glaze, simmer the reserved sauce in a small saucepan over medium heat for 5-8 minutes until slightly reduced and syrupy.
Step 6: Brush the easy huli huli chicken sauce generously onto the chicken during the last 10 minutes of grilling, turning the meat frequently to prevent burning while building a thick glaze.