Marinate the chicken: In a large bowl, mix the chicken cubes with chilli powder, Thai 5 spice, cumin powder, coriander powder, soya sauce, white pepper, aromat, and chilli sauce. Adding the spices and sauces first allows the chicken to soak in all the flavors. Then, mix in the eggs and corn flour to create a batter that will crisp up when fried.
Fry the chicken: Heat oil in a deep pan over medium-high heat. Once hot, fry the marinated chicken pieces in batches until golden brown and crispy. The combination of eggs and corn flour creates a crunchy exterior, while the chicken stays juicy inside. Once done, set the chicken aside on paper towels to drain excess oil.
Prepare the sauce: In a large pot, heat a bit of oil over medium heat. Add the chopped onion and garlic, and sauté until the onion turns translucent and slightly pink. The gentle cooking releases the sweetness from the onion and mellows the sharpness of the garlic. Add the chopped green and red peppers and cook for another few minutes. The peppers should soften but still retain some crunch.
Add the sauces and spices: Pour in the tomato sauce, Maggi chilli sauce, Sriracha sauce, and Tabasco sauce. Add the zeal salt, white pepper, chilli powder, and salt. Stir to combine, allowing the sauces to mix well and the spices to bloom, creating a rich and flavorful base for the chicken.
Simmer the sauce: Add 1 cup of water to the pot and bring it to a gentle boil. This helps to meld the flavors together and allows the sauce to thin out slightly. Cook for 2-4 minutes to reduce slightly.
Thicken the sauce: In a small bowl, mix 2 tablespoons of corn flour with 1/4 cup of water to create a slurry. Slowly pour the slurry into the boiling sauce, stirring constantly to prevent lumps. This thickens the sauce to the perfect consistency, coating the chicken beautifully.
Combine the chicken and sauce: Add the fried chicken to the sauce and stir until all the pieces are evenly coated. Allow the chicken to simmer in the sauce for 10 minutes, letting the flavors meld together. If the sauce feels too thin, you can simmer it longer or add a bit more corn flour slurry.
Finish and serve: Sprinkle sesame seeds over the chicken and serve hot with naan, rice, or potato wedges. The sesame seeds add a lovely nutty crunch that complements the spicy, tangy sauce.