Prepare Coating: Mix flour, cornmeal, cornstarch, nutritional yeast, seasoning, baking soda, and salt in a bowl.
Rehydrate Soy Curls: Soak soy curls in hot vegan broth for 5 minutes, then toss them in the dry coating mixture.
Bread the Chicken Substitute: Wet tofu, vegan chicken strips, or thawed frozen substitutes and coat them in the breading mixture.
Deep Fry: Heat oil in a deep fryer to 370°F (188°C) and fry breaded pieces for 3 minutes or until golden.
Pan Fry: Heat oil in a frying pan, fry breaded pieces for 3-4 minutes per side, and drain on paper towels.
Bake (Optional): Bake breaded pieces on a parchment-lined baking sheet at 425°F (220°C) for 7 minutes per side, spraying with oil.
Serve warm and enjoy your crispy vegan popcorn chicken!