Step 1: Preheat and Prep
Preheat your oven to 375°F (190°C). Lightly grease a 9×13-inch baking dish and set it aside. If you haven’t already, cook your chicken and shred it, or use rotisserie chicken to save time. Also, cook your rice or quinoa if using it as a base layer.

Step 2: Sauté the Aromatics
In a large skillet, heat the olive oil over medium heat. Add the diced onion and cook until translucent, about 4–5 minutes. Stir in the minced garlic and cook for another minute until fragrant.

Step 3: Add Bell Peppers and Pineapple
Toss in the chopped red and green bell peppers, along with the pineapple chunks. Cook for another 3–4 minutes to soften the peppers and start caramelizing the pineapple slightly. This step boosts the natural sweetness and depth of flavor.

Step 4: Make the Sauce
Lower the heat slightly and add the tomato paste, soy sauce, pineapple juice, honey, vinegar, chili garlic sauce, paprika, and red pepper flakes (if using). Stir everything together until well combined. Let it simmer for 5 minutes until slightly thickened. Taste and adjust seasoning with salt and black pepper.

Step 5: Combine Chicken and Sauce
Add the shredded chicken to the skillet and stir until it’s evenly coated in the spicy pineapple sauce. Let it simmer for 2 more minutes so the flavors meld together.

Step 6: Assemble the Casserole
If using rice or quinoa, spread it evenly in the bottom of your greased casserole dish. Pour the spicy pineapple chicken mixture over the top and spread it out evenly. Sprinkle with shredded cheese if you’re using it.

Step 7: Bake Until Bubbly
Place the casserole in the preheated oven and bake for 20 minutes, or until everything is bubbling and the cheese is melted and golden.

Step 8: Garnish and Serve
Remove from the oven and let it cool slightly. Sprinkle with chopped cilantro or green onion just before serving for a fresh pop of color and flavor.