Preheat oven to 400°F (200°C) and line a baking sheet with parchment or foil.
In a bowl, whisk together soy sauce, brown sugar, Worcestershire, pineapple juice, cornstarch, olive oil, ginger, garlic, and crushed red pepper.
Add diced chicken, peppers, onion, and pineapple to the bowl and toss to coat.
Spread everything evenly on the prepared sheet pan.
Bake for 25 minutes, or until the chicken is fully cooked and slightly caramelized.
Remove from oven, garnish with fresh herbs (optional), and serve hot.