Sweet and Sour Pork (咕噜肉或古老肉 Gu lu Rou / Gu Lao Rou)

Gather all the ingredients. Chop the pineapple and bell pepper into ~1 inch (2.5 cm) long sized pieces. Cut the pork belly or pork tenderloin into 0.6-1 inch (2-2.5 cm) long cubes and put them in a deep bowl or large plate. Add the ¼ teaspoon kosher salt and ¼ teaspoon black pepper to the pork cubes and mix well. Then evenly coat the pork cubes with the 3 tablespoons of corn starch. If using pork tenderloin or other lean pork meat, after the pork is well mixed with salt and pepper, beat an egg and dip the pork meat first in the egg mixture before coating with corn starch.

Add 2 cups of vegetable oil into a small sauce pan and turn the heat to medium high. When the oil temperature reaches 350 °F (175 °C) degree, add the pork belly cubes slowly into the hot oil. (If you have no thermometer, stick a wooden chopstick into the oil. If bubbles start forming around the chopstick and then float up, the oil should be ready).

Fry the pork meat for 1-2 minutes until pale golden. Then immediately transfer them to a plate lined with paper towel. Allow the oil in the sauce pan to rise to 350 °F (175 °C) again. Then add the pork cubes back into oil to fry for a second time. Transfer them to a plate lined with new paper towel after 1-2 minutes. The color of the fried pork cubes after double frying should be a shade darker than the first time.

Heat a skillet with medium-high heat and add 1 tablespoon of the oil that was left from frying. When the oil is getting hot, add the green onion pieces. After about 10-15 seconds, when the green onion’s fragrance is released, add the chopped bell pepper and immediately toss and stir. Transfer the bell pepper pieces onto a plate when they are only about 80% cooked.

In a small bowl, prepare the sauce mixture by combining all the sauce ingredients: ¼ cup ketchup, ¼ teaspoon salt, 1 tablespoon sugar, 1 tablespoon vinegar, and 2 tablespoon water. Add the leftover amount of corn starch from coating the pork meat and mix well.

In the same skillet at medium-high heat, add another 1 tablespoon of oil from the oil that was left over from frying. While the oil is warm but not hot, pour the sauce mixture into the skillet. Quickly toss and stir to prevent splattering; about 30 seconds.

While the sauce is hot, add the chopped pineapple, 80% cooked bell pepper chunks, and double fried pork cubes all at once to the sauce skillet. Immediately toss and stir for about 1-2 minutes until all the pork cubes are evenly coated with sauce. This final step needs to be done fast to ensure the pork remain tender and crisp.

Transfer to a large plate and serve.