Prepare the chicken: Trim the chicken breast to get rid of any excess fat and cartilage. Butterfly the chicken breasts so that they are about ½ inch thick. Then, cut the chicken against the grain into finger-size strips. Place the prepared chicken into a large mixing bowl and add the rice wine, salt, and egg. Mix everything together until well combined. Set aside and allow the chicken to marinate for about 10 to 15 minutes as you prepare the rest of the ingredients, or overnight in the fridge.

Make the batter: In a bowl, whisk together the self-rising flour, cornstarch, baking powder, and salt. Then add the water and egg and mix until no more dry clumps of flour is visible. Add the oil and vinegar and mix until well combined. Set aside until needed.

For the sweet and sour sauce: Into a saucepan, mix together water, pineapple juice, vinegar, ketchup, sugar, salt, and the red food coloring. Bring the sauce to a boil while mixing occasionally until the sugar and salt has dissolved. Reduce the heat to low. Give the prepared cornstarch slurry a mix to combine. While stirring the sweet and sour sauce, slowly drizzle in the cornstarch slurry. Once added, increase the heat so that the sauce comes back to a simmer and allow the sauce to cook until it's thickened and glossy. Set the finished sauce aside and keep it covered until needed.

Make the sweet and sour chicken: In a wok or pot, heat up 2 to 3 inches of oil to 350°F. While the oil is heating up, give the marinated chicken a good mix. Then add the prepared batter to the chicken and mix until the chicken pieces are all well coated.

For the 1st fry: When the oil is hot, gently add the chicken pieces one at a time. Fry in batches if necessary. Allow the chicken to fry for about 4 to 5 minutes, or until they float to the surface and start to turn pale golden on all sides. Remove from the oil and allow the chicken to drain and cool on the prepared plate lined with paper towels for about 5 minutes.

For the 2nd fry: After resting, add the chicken back into the oil at 350°F and fry for another 3 to 4 minutes, or until the chicken is golden brown and crispy on the outside. Remove and allow the oil to drain.

Cook the veggies: In a pot of boiling water, add the bell peppers and carrots. Allow them to cook for about 15 seconds then add the onions. Let the veggies cook for an additional 5 to 10 seconds or until they are to your desired tenderness and drain well.

Assembly: Toss together the fried chicken pieces, the blanched veggies, and pineapple chunks. Then transfer it to a serving plate. Serve the sweet and sour chicken immediately and either pour the sauce over everything or serve the sauce on the side to dip.