Start by cutting the boneless skinless chicken thighs into 1-inch pieces, placing them in a bowl. Season the chicken generously with salt and pepper before coating it in beaten eggs for a flavorful binding agent. Cover the bowl with plastic wrap and refrigerate for about 15 minutes.

While the chicken is marinating, dice the bell peppers, pineapple, and red onions into 1-inch pieces. Set aside the chopped ingredients in separate bowls, ready for quick assembly.

In a medium mixing bowl, combine the ketchup, rice vinegar, brown sugar, grated ginger, minced garlic, and chicken base to create a luscious sauce. Whisk until well blended, ensuring there are no lumps. Set the sauce aside.

Take about a quarter of the sauce and pour it into a small bowl. Mix in cornstarch until smooth for your slurry. Set this aside for the next step.

Prepare a dredging station by mixing cornstarch and flour in another shallow dish. Coat each marinated chicken piece in the mixture before placing it on a parchment-lined tray.

In a large skillet, heat oil to 350°F (175°C) over medium-high heat. Fry the chicken pieces in batches for 3 to 4 minutes until they are golden brown and crispy. Use a slotted spoon to remove them and let them drain on paper towels.

In the same skillet, add the chopped bell peppers, pineapple, and red onions. Sauté over medium heat for about 5 minutes or until tender yet still vibrant.

Pour the prepared sauce into the skillet, bringing it to a gentle boil over medium heat. Quickly stir in the prepared slurry, cooking for about 2 minutes until the sauce thickens. Add the fried chicken pieces, allowing them to heat through for another minute.

Plate your Sweet and Sour Chicken alongside steaming jasmine or basmati rice, garnishing with additional vegetables or fresh herbs for a burst of color and flavor.