Drain pineapple chunks, reserving the juice. Set pineapple chunks aside.

Prepare the sauce: In a bowl, whisk together the reserved pineapple juice, orange juice, vinegar, soy sauce, cornstarch, onion powder, red pepper flakes, and ground ginger.

Preheat a large skillet or wok over high heat.

Add safflower oil to the hot skillet.

Stir-fry the thawed broccoli for about 2 minutes, or until crisp-tender. Remove the broccoli from the skillet and set aside.

Add the bite-sized chicken breast pieces to the skillet and stir-fry for 2-3 minutes, or until cooked through.

Push the cooked chicken to the side of the skillet/wok.

Stir the sauce mixture to ensure the cornstarch is well-distributed. Pour the sauce into the center of the skillet.

Cook and stir the sauce until it thickens and becomes bubbly. Continue to cook and stir for an additional 2 minutes.

Stir the broccoli back into the skillet, combining it with the chicken and sauce.

Reduce the heat to medium.

Add the reserved pineapple chunks to the skillet.

Cover the skillet and cook for about 1 minute, or until everything is heated through.

Serve the hot Hawaiian chicken stir-fry over chow mein noodles or cooked rice.