Hydrate & Infuse the Batter : In a medium bowl, whisk together the chickpea flour, lukewarm water, 1 tbsp extra virgin olive oil, minced garlic, dried oregano, black pepper, and the pinch of sea salt until no lumps remain. Cover the bowl and let the batter rest at room temperature for 1 hour. This crucial step allows the flour to fully hydrate, resulting in a superior texture.
Temper the Pan : About 15 minutes before the batter is ready, adjust your oven rack to the middle position and preheat to 450°F (230°C). Place a 10-inch cast-iron skillet in the oven to get scorching hot.
Forge the Foundation : Wearing sturdy oven mitts, carefully remove the preheated skillet from the oven. Add 1 tbsp of the remaining olive oil to the skillet, swirling quickly to coat the bottom. Give the socca batter a final whisk and immediately pour it into the hot skillet. It should sizzle on contact. Place the skillet back into the oven and bake for 10-12 minutes, or until the edges are set, golden brown, and pulling away from the sides.
Assemble the Garden Layer : While the socca bakes, prepare the squash. Using a vegetable peeler, shave the zucchini and yellow squash lengthwise into thin ribbons. In a small bowl, toss the ribbons with the final 1 tbsp of olive oil. Once the foundation is set, remove the skillet from the oven. Quickly work to layer the toppings: first, wilt the spinach directly on the hot socca surface. Spread the tomato passata evenly over the spinach. Artfully arrange the squash ribbons over the sauce, followed by the artichoke hearts and halved cherry tomatoes.
The Final Bake : Sprinkle the crumbled feta and pumpkin seeds over the vegetables. Return the skillet to the oven and bake for an additional 5-6 minutes, just until the vegetables are tender-crisp and the feta is slightly softened.
Garnish and Serve : Remove the flatbread from the oven. Garnish immediately with fresh thyme leaves and another crack of black pepper. Let it rest in the skillet for 2-3 minutes before carefully sliding it onto a cutting board. Slice into 3 equal portions and serve warm.