Heat the oven: Preheat to 425°F (220°C). Line a large sheet pan with parchment for easy cleanup.
Mix the marinade: In a bowl, whisk soy sauce, pineapple juice, honey, rice vinegar, lime zest and juice, garlic, ginger, sriracha (if using), and 1 tablespoon oil.
Taste and adjust sweetness or acidity.
Prep the chicken: Pat dry and cut thighs into 1.5-inch pieces (or leave whole if you prefer). Toss half the marinade with the chicken. Let sit 10–20 minutes while you prep veggies.
Prep the veggies: Slice bell peppers and onion.
If using snow peas, leave whole. Toss veggies and pineapple chunks with the remaining 1 tablespoon oil, a pinch of salt, and black pepper.
Arrange on the pan: Spread veggies and pineapple across the pan in a single layer. Nestle marinated chicken pieces on top, leaving space so things can brown.
Roast: Bake 18–22 minutes if chicken is in pieces, or 22–28 minutes if thighs are whole.
Stir once halfway to caramelize evenly. Chicken is done at 165°F (74°C).
Optional glaze finish: Pour the leftover marinade into a small saucepan. Bring to a boil, whisk in 1 teaspoon cornstarch mixed with 1 teaspoon water, and simmer 1–2 minutes until glossy.
Drizzle over the sheet pan for extra shine and flavor.
Broil for color: For charred edges, broil 1–2 minutes at the end. Keep a close eye to avoid burning.
Garnish and serve: Sprinkle green onions and sesame seeds. Serve over rice or greens, with lime wedges on the side.