Whisk the Shaoxing wine, soy sauce, sugar, sesame oil, broth, and cornstarch in a small bowl until the starch is completely dissolved and set aside.

Slice the eggplants horizontally in half, then into 1-inch-thick angled pieces. Toss them with salt in a large bowl and cover with room-temperature water. Soak for 10 minutes to draw out bitterness and improve the final texture.

Slice the potato and both bell peppers into 1-inch pieces while the eggplant soaks.

Drain the eggplant and pat it thoroughly dry with paper towels—moisture is the enemy of a crisp crust. Toss the dry eggplant with cornstarch until every piece is well-coated.

Heat a large skillet or wok over medium-high heat and add the oil. When the oil shimmers, fry the potatoes for 3-4 minutes per side until they are golden brown and fork-tender, then remove them from the pan.

Add the cornstarch-coated eggplant to the same pan. Cook over medium-high heat for 4-5 minutes, turning occasionally so the edges get crisp and the interior becomes velvety. Remove the eggplant from the pan.

Lower the heat to medium and sauté the scallions and garlic until tender and fragrant, about 2 minutes.

Increase the heat to high and add the bell peppers. Sauté for 2 minutes, just until they are slightly tender but still bright and snappy.

Lower the heat back to medium. Give the sauce a quick stir to re-incorporate the cornstarch, then pour it into the pan. Stir constantly with a spatula until the liquid bubbles and thickens into a glossy glaze, about 2 minutes.

Return the potatoes and eggplant to the pan. Toss for another 2 minutes over medium-high heat until the sauce is fully absorbed and the vegetables are hot and glazed. Season with additional salt to taste and serve immediately with steamed rice.