Preheat your oven to 350°F (180°C). Grease a 9-inch pie dish or springform pan and line the bottom with a round of parchment paper.

Combine the  eggs, milk, olive oil, drained chickpeas, oat flour, garlic, parmesan cheese, black pepper and baking powder in a high-speed blender container. Process on high for 60–90 seconds until the mixture is completely homogeneous, smooth, and velvety. The consistency should resemble a thick, rich pancake batter.

Add the intensely wrung-out spinach, chopped sun-dried tomatoes, cubed feta cheese and finely chopped basil. Using a flexible spatula, gently fold the mix-ins into the batter until evenly distributed.

Pour the finished mixture into your prepared pan, smoothing out the top surface with your spatula. Transfer to the center rack of the oven and bake for 35 to 40 minutes. The pie is done when the surface is golden brown, the edges pull slightly away from the pan walls, and a toothpick inserted into the absolute center comes out clean.

Remove from the oven and allow the pie to cool in the pan for a mandatory 10 minutes. This ensures perfectly clean, beautiful slices for presentation. Slice into wedges and serve warm or at room temperature.