Remove the stems from the eggplants and cut them into 1½-inch pieces using a roll-cut technique. Toss with cornstarch and a teaspoon of water to coat, then set aside.

Peel and cube the potatoes into 1-inch pieces, cut the bell pepper into triangles, mince the garlic and ginger, and slice the scallion.

In a small bowl, whisk together cornstarch, light soy sauce, oyster sauce, sugar, dark soy sauce, and kosher salt with ½ cup of water until smooth.

Heat 2 cups of vegetable oil in a wok to 320°F (160°C). Fry the potatoes for 5-6 minutes or until golden and crispy, then drain on paper towels.

Increase the oil temperature to 355°F (180°C) and fry the eggplant until the edges are brown and soft—about 2-4 minutes. Drain on paper towels.

Fry the bell pepper in the residual heat for about 1 minute, then drain.

In the clean wok, heat 1 tablespoon of oil over medium heat. Add ginger, scallions, and half of the minced garlic. Stir-fry for about 30 seconds until fragrant.

Pour in the sauce mixture and simmer for about a minute until thickened, whisking constantly.

Add the crispy potatoes, eggplant, and bell pepper to the wok, tossing everything to coat evenly for about 2 minutes.

Finish by adding the remaining garlic and tossing for an additional 30 seconds before removing from heat.