Step 1: In a medium bowl, whisk together the soy sauce, rice vinegar, granulated sugar, hoisin sauce, sesame oil, and red pepper flakes until the sugar is mostly dissolved.
Step 2: In a separate small bowl, create a cornstarch slurry by whisking together the cornstarch with 2 tablespoons of cold water or chicken broth until smooth and lump-free.
Step 3: Heat 1 tablespoon of vegetable oil in a small saucepan or wok over medium heat. Add the minced garlic and grated fresh ginger. Sauté for 30 seconds to 1 minute, stirring constantly, until fragrant. Be careful not to burn them.
Step 4: Pour the prepared sauce mixture from Step 1 into the saucepan with the aromatics. Bring the mixture to a gentle simmer, stirring occasionally.
Step 5: Give the cornstarch slurry another quick whisk (as cornstarch can settle). Slowly pour the slurry into the simmering sauce while continuously stirring. Continue to stir for 1-2 minutes until the sauce thickens to a glossy consistency that coats the back of a spoon.
Step 6: Remove the General Tso sauce from the heat. Taste and adjust the seasoning as needed. You can add more sugar for sweetness, more red pepper flakes for heat, or a dash more rice vinegar for tang.
Step 7: Your homemade General Tso sauce is now ready to use! Toss it with crispy chicken, tofu, shrimp, or your favorite stir-fried vegetables and serve immediately over rice or noodles.