Preheat oven to 325° F.: As you heat the oven, you will notice a gentle warmth building in the kitchen that sets the stage for slow, even cooking. This lower and steadier temperature helps the sauce thicken without the chicken drying out, producing tender meat and a caramelized top. Listen for the faint hum of the oven into which the aromas will later concentrate. A common mistake at this stage is rushing and setting the oven to a much higher temperature, which can overbrown the surface while leaving the interior dry. If your oven runs hot, use an oven thermometer to confirm the temperature for accuracy.
Grease a 9 x 13-inch baking pan with cooking spray and set aside.: Coating the pan ensures the sauce does not glue itself to the dish, and it will make lifting pieces easier once cooked. The metal or glass will both heat differently, so choose the one you are familiar with to judge baking times. You might hear a faint sizzle if the spray meets a very hot pan, but normally it remains quiet. Avoid using too much spray, which can pool and cause the sauce to slide.
Add chicken to a large bowl and season it with salt and pepper.: After seasoning, the chicken should smell lightly of salt and pepper, which primes the meat to take on the sauce flavors. Seasoning early helps the meat absorb the flavors rather than just coating the surface. A frequent error is under seasoning, leaving the final dish bland, so taste a small cooked scrap to check if you need more.
Place cornstarch in a large bowl, and eggs in another medium bowl.: Setting up a tidy dredging station helps maintain even coating and prevents clumping. The visual contrast between the dry cornstarch and the glossy beaten eggs signals the order of operations. If the cornstarch gets wet, it will cake, so keep the bowls separate and dry. Messy stations lead to uneven coatings, so line a tray to hold dredged pieces.
Dip seasoned chicken pieces in cornstarch to coat, then coat in eggs.: As you dredge each cube, you'll feel a light powder cling to the surface, then the egg will make it tacky and ready to hold during searing. This two step process builds a thin barrier that crisps and helps the sauce adhere. If your hands are damp, the cornstarch will clump, so dry them between pieces. Skipping the cornstarch yields a softer exterior and less textural contrast.
Place a large non-stick skillet over medium-high heat. Add vegetable oil.: The oil should shimmer but not smoke, signaling it is hot enough to sear. When you test with a small breadcrumb, it should sizzle on contact. This step is crucial because a properly hot pan creates a Maillard reaction, producing golden brown color and savory depth. If the oil smokes, lower the heat, because burnt oil brings bitter notes. Using too little oil results in sticking and uneven browning.
Once the oil is hot, cook coated chicken, in batches so you don't over-crowd pan, until golden-brown on all sides.: You will hear a confident sizzle as the pieces hit the pan and see the edges turn from pale to golden in just a couple of minutes per side. Cooking in batches preserves pan heat and ensures quick browning, instead of steaming the meat. Overcrowding creates pale, soggy pieces, so give them space and transfer to a tray between batches. A common oversight is trying to rush by adding too many pieces at once, which prevents proper crust formation.
Once cooked, place the chicken in the prepared baking dish.: As the browned cubes collect in the dish, you will notice an enticing aroma of caramelized chicken . Arranging them evenly helps the sauce coat every piece during baking. If you pile them, the sauce may pool and not penetrate evenly. Let any excess oil drip off briefly to avoid an oily final sauce.
In a medium bowl whisk together all the sauce ingredients. Pour evenly over the chicken.: Whisking combines the pineapple juice, orange juice, lime juice, brown sugar, low sodium soy sauce , rice vinegar, minced garlic , lime zest and a bit of cornstarch for body. As you whisk you will see the sugar dissolve and the mixture take on a glossy sheen, smelling bright and sweet. Pouring it over the chicken ensures each piece will bathe in flavor as it bakes. If the sauce looks too thin, you can mix a small additional cornstarch slurry, but adding too much will make it gummy.
Distribute the chopped bell pepper and pineapple evenly on top of the chicken.: The peppers add pops of color and a crisp counterpoint while the pineapple gives juicy sweetness and texture. Scatter them so each portion gets both elements after baking. The visual contrast is part of the appeal, and the juices from the pineapple will mingle with the sauce as it heats. Ensure the pineapple is drained well, because excess liquid can thin the sauce and extend baking time.
Bake, uncovered, for 1 hour, stirring the mixture a few times.: During baking the kitchen will fill with a warm, fruity aroma while the sauce reduces and thickens into a shiny glaze. Stirring a couple of times promotes even coating and prevents the bottom from sticking, allowing the chicken to absorb the sauce. Baking uncovered encourages slight caramelization on top. A mistake is leaving it untouched for too long, which may cause uneven browning or parts to dry; brief gentle stirring avoids that.
Remove from the oven and let stand 10 minutes before serving.: Letting the dish rest allows the sauce to cool and thicken slightly, making it cling better to the chicken and making serving neater. The aromas will settle and the temperature will even out, which is kinder to the palate. Serving immediately can cause the sauce to run and be overly hot, risking burns or a loose texture.
Serve over rice, garnish with green onions and sesame seeds.: As you plate, the contrast of fluffy rice under sticky, glossy chicken pieces is comforting and visually appealing. The green onions add a fresh bite and the sesame seeds contribute a nutty crunch. Garnish just before serving so the green onions remain vibrant. Avoid garnishing too early, which will cause the herbs to wilt and lose color.