Preheat the oven to 400°F.
In a small bowl, whisk the egg white. Set aside a shallow dish with almond flour.
Dip the chicken breast in the egg white, then coat it evenly with the almond flour.
Place the coated chicken on a baking sheet lined with parchment paper.
In another bowl, toss the red bell pepper, broccoli, zucchini, and minced garlic with olive oil. Spread them out on a separate baking sheet.
Bake the chicken for 20-25 minutes until cooked through and the coating is crispy.
Roast the vegetables in the oven for about 20 minutes, stirring halfway through, until tender and lightly charred.
While the chicken and vegetables are baking, prepare the sweet and sour sauce by combining the pineapple chunks, honey, rice vinegar, and a pinch of minced garlic in a small saucepan over medium heat. Simmer for 3-5 minutes until slightly thickened.
Once everything is done, plate the crispy chicken, spoon over a light drizzle of the sweet and sour sauce, and serve alongside the roasted vegetables.