Prepare the sauce by combining Soy Sauce (3 tablespoon), Apple Cider Vinegar (2 tablespoon), Dark Soy Sauce (1 teaspoon) and Brown Sugar (2 teaspoon).
In a separate small bowl, mix the Corn Starch (3/4 teaspoon) with Water (1 1/2 tablespoon). Stir well to remove any clumps.
Heat Cooking Oil (2 tablespoon) in a wok over medium high heat. Add Lotus Root (2 cup) and stir-fry until slightly brown; about 2 minutes.
Add Garlic (2 clove) to the wok and stir-fry until aromatic; about 20 seconds.
Stir in the sauce, toss to coat the lotus root slices.
Drizzle in the cornstarch mixture. It should thicken immediately. Give it a quick stir, then turn off the heat.
Transfer the dish to a serving plate, then garnish with Scallion (to taste) and Red Chili Pepper (to taste).