Preheat your oven to 425°F and line a baking sheet with parchment paper.
Cut the chicken breast into bite-sized pieces and pat dry with paper towels.
In a small bowl, lightly beat the egg white. In another bowl, add the panko bread crumbs.
Dip each chicken piece first into the egg white, then coat evenly with panko crumbs, pressing gently to adhere.
Place the coated chicken pieces on the prepared baking sheet in a single layer.
Bake for 15-18 minutes until the chicken is crisp and cooked through, flipping halfway for even crispiness.
While the chicken bakes, prepare the sweet and sour sauce. In a small saucepan, combine the pineapple chunks, red bell pepper (diced), rice vinegar, honey, water, and cornstarch. Stir well.
Bring the mixture to a simmer over medium heat, stirring continuously until the sauce thickens (about 3-4 minutes).
Once the chicken is done, drizzle the warm sweet and sour sauce over the crispy baked chicken or serve on the side for dipping.
Serve immediately and enjoy your healthy, flavor-packed meal!