Make the sauce: Place pineapple juice, rice vinegar, brown sugar, ketchup, cornstarch, soy sauce and food coloring (if using) in a medium sized dish. Whisk ingredients until smooth. Set sauce aside.
Prepare 3 bowls with ingredients to coat the pork pieces. One with corn starch, one with flour, and one with slightly beaten eggs. Dredge the pork pieces in cornstarch (a couple pieces at a time), then dip in egg to cover, and then coat the pieces in flour. As you finish coating each piece, place onto a baking sheet.
Pour oil into a large skillet to a depth of 2-3 inches. Heat oil on medium high heat until very hot (but not smoking). TIP: You will need to cook the pork in batches, reheating oil in between batches! Don't overcrowd the skillet, because you want the pork to cook evenly on all sides. Carefully add the coated pork pieces into hot oil. Cook pork for 2-3 minutes, turning once, until cooked through, golden brown, and crispy on the outside. Once done, carefully remove the pork pieces with a slotted spoon (so oil drips back into skillet), and place onto a baking sheet. Repeat until all pork is cooked.
In a separate large skillet, add 2 Tablespoons oil; heat on medium high. Once oil is hot, add pineapple, bell peppers, and onion. Cook, stirring occasionally for 3 minutes. Veggies should be tender, and slightly crisp when done. Add sauce to skillet. Stir to combine, and heat through. Sauce will thicken slightly as it cooks. Right before you're ready to serve, add browned pork back into the skillet; stir to combine. Heat only until the pork is heated through, and then the sweet and sour pork is ready to eat! Serve on top of rice. Enjoy!
Caloric calculation made based on the use of pork butt.
Sweet and Sour Pork https://www.thegratefulgirlcooks.com/sweet-sour-pork/