Preheat your oven to 400°F and line a baking sheet with parchment paper.
Slice the chicken breast into strips or bite-sized pieces.
In a shallow bowl, mix the almond flour with garlic powder, salt, and pepper.
Lightly whisk the egg white in a separate bowl.
Dip each piece of chicken first into the egg white, then coat thoroughly in the almond flour mixture.
Place the coated chicken pieces on the prepared baking sheet and bake for 15-20 minutes, flipping halfway, until the exterior is crisp and the chicken is cooked through.
While the chicken bakes, prepare the sweet and sour sauce by combining pineapple chunks, red bell pepper, red onion, low-sodium soy sauce, rice vinegar, honey, and a dash of salt and pepper in a small saucepan. Simmer for 3-4 minutes until the vegetables are slightly softened and the flavors meld.
Once the chicken is cooked, gently toss it in the warm sweet and sour sauce or serve the sauce on the side as a dip.
Plate the dish and enjoy your crispy, tangy, and healthy sweet and sour chicken.