Chinese Sweet and Sour Pork

For the Marinade: In a medium bowl, whisk Shaoxing wine, egg, egg white, baking soda, white pepper, oil, potato starch or cornstarch, and salt to combine. Add pork and toss to coat evenly. Let sit for at least 15 minutes or up to 2 hours in the refrigerator.

For the Dredge: In a medium bowl, whisk potato starch or cornstarch, baking powder, and salt to combine. Add 3 tablespoons (45 ml) of prepared marinade to starch mixture and, using a fork, stir until small, pea-size clumps form, using your fingers to break up any large pieces.

Set aside a clean baking sheet or large plate. Working one piece at a time, lift pork from the marinade, let any excess liquid drip back into the bowl, then transfer to dredge, pressing gently to adhere as much of the coating as possible. Place the coated pork on the baking sheet or plate. Repeat with remaining pork.

In a large wok, heat oil to to 325°F (165°C). Working in batches to avoid overcrowding, fry pork, adjusting heat as necessary to maintain temperature, until the coating sets and just begins to take on color, about 2 minutes per batch. Use a slotted spoon or spider skimmer to transfer pork to a paper towel–lined plate; set aside.

Increase oil temperature to 375°F (190°C). Working in batches to avoid overcrowding, fry pork again, until deeply golden and crisp, about 1 to 1 1/2 minutes per batch. Use a slotted spoon or spider to transfer pork to a paper towel-lined plate; set aside.

Add bell peppers and pineapple to the hot oil and fry until just slightly softened and blistered in spots, about 1 minute. Transfer to a separate paper towel–lined plate to drain.

For the Sauce: Using oven mitts or a kitchen towel, carefully pour frying oil into a large heat-proof bowl or container, reserving 1 tablespoon in the wok. (Reserve leftover oil for another use.) Reduce heat to medium. In a medium bowl, whisk ketchup, vinegar, 2 tablespoons (30 ml) water, sugar, and salt to combine. Add ketchup mixture to the wok and cook, stirring constantly, until the mixture begins to bubble and sizzle.

In a small bowl, whisk cornstarch with remaining 1 tablespoon (15 ml) water to make a slurry. Stir slurry into the bubbling sauce and cook, stirring, until thickened and glossy, about 30 seconds. The sauce should coat a spoon and fall in thick ribbons.

Add the fried pork, bell peppers, and pineapple to the wok. Toss quickly but thoroughly to evenly coat ingredients in the sauce. Serve immediately.