Preheat the oven to 425°F and line a baking sheet with parchment paper.
Slice the chicken breast into bite-sized strips or small pieces, then season lightly with salt and pepper.
In a shallow bowl, mix the panko bread crumbs with a pinch of salt and pepper.
In another bowl, whisk the egg whites until slightly frothy.
Dip each piece of chicken first in the egg whites, then coat evenly with the panko mixture.
Place the coated chicken pieces onto the prepared baking sheet and lightly drizzle with olive oil.
Bake in the preheated oven for 15-18 minutes, flipping halfway through, until the coating is crisp and the chicken is cooked through.
Meanwhile, prepare the sweet and sour sauce by combining pineapple juice, rice vinegar, honey, minced garlic, and grated ginger in a small saucepan. Heat gently over low-medium heat until the mixture simmers briefly and the flavors meld. Adjust seasoning if necessary.
Once the chicken is done, drizzle the warm sweet and sour sauce over the crispy chicken pieces or serve it on the side as a dip.
Serve immediately and enjoy your balanced, delicious dish.