1. Preheat Your Oven and Prepare the Crust: Preheat your oven to the temperature recommended on your sourdough pizza crust packaging, usually around 400-425 F (200-220 C). Place the sourdough crust directly on a baking sheet.

2. Saute the Heartier Vegetables: In a medium skillet, heat 1 tablespoon of olive oil over medium heat. Add the trimmed asparagus pieces and sliced red onion. Saute for 3-5 minutes, or until the asparagus is tender-crisp and the onion is slightly softened. Add the minced garlic during the last minute of cooking. Season with a pinch of salt and pepper.

3. Assemble the Flatbread Base: Drizzle a little extra olive oil over the sourdough crust. Spread the sauteed asparagus and red onion evenly over the crust.

4. Add Remaining Vegetables and Cheese: Scatter the halved cherry tomatoes, sliced bell pepper, and fresh spinach over the flatbread. Top with the shredded mozzarella cheese and crumbled goat cheese, if using.

5. Bake Until Golden and Bubbly: Place the baking sheet with the assembled flatbread into the preheated oven. Bake for 12-15 minutes, or until the crust is golden brown and crispy, and the cheese is melted and bubbly. Keep an eye on it to prevent over-browning.

6. Finish and Serve: Carefully remove the flatbread from the oven. Let it cool for a minute or two before garnishing with fresh basil leaves. Slice into wedges or squares and serve immediately.