1. 1. Prepare the Frittata Batter: In a large mixing bowl, whisk together the chickpea flour, nutritional yeast, black salt (if using), garlic powder, onion powder, turmeric, and black pepper. Gradually pour in the plant-based milk, whisking continuously until you have a smooth batter with no lumps. Stir in the sourdough starter discard until well combined. Set the batter aside to rest while you prepare the vegetables. This resting period allows the chickpea flour to fully hydrate, resulting in a better texture.

2. 2. Saute the Vegetables: Heat 1 tablespoon of olive oil in a 10-inch oven-safe, non-stick skillet (or cast-iron skillet) over medium heat. Add the diced onion and cook for 3-5 minutes, until softened and translucent. Add your chosen winter vegetables (e.g., kale, mushrooms, bell peppers) and continue to cook, stirring occasionally, until they are tender-crisp and any excess moisture has evaporated, about 5-7 minutes. If using leafy greens like spinach, add them in the last 2 minutes until just wilted.

3. 3. Preheat Oven and Combine: While the vegetables are cooking, preheat your oven to 375 F (190 C). Once the vegetables are ready, spread them evenly across the bottom of the skillet.

4. 4. Pour and Cook on Stovetop: Pour the prepared chickpea flour and sourdough batter evenly over the sauteed vegetables in the skillet. Let it cook on the stovetop over medium-low heat for 3-5 minutes, or until the edges of the frittata begin to set and pull away slightly from the sides of the pan. This initial stovetop cooking helps create a nice crust on the bottom.

5. 5. Transfer to Oven and Bake: Carefully transfer the skillet to the preheated oven. Bake for 15-20 minutes, or until the frittata is firm to the touch in the center and lightly golden brown on top. You can test for doneness by gently pressing the center; it should feel solid and not jiggly.

6. 6. Cool and Garnish: Once baked, remove the skillet from the oven and let the frittata cool in the pan for 5-10 minutes before slicing. This cooling period allows it to set completely and makes for cleaner slices. Garnish with fresh chopped parsley before serving.