Soak the Lentils: Place the dry red lentils in a large bowl, cover generously with cold water, and soak for 2–3 hours. Drain and rinse thoroughly in a fine-mesh colander, shaking off excess moisture.
Preheat & Prep: Preheat your oven to 400°F (200°C). Line a large baking sheet with parchment paper.
Blend the Crust Batter: Add the thoroughly drained lentils to a high-speed blender along with 320 ml fresh water, olive oil, baking powder, salt, Italian seasoning, garlic powder, and optional oat flour. Blend on high until completely smooth into a thick, pourable batter.
Spread the Batter: Pour the batter onto the prepared baking sheet and spread it evenly into a thin layer (approximately 1/4-inch thick) to ensure a crispy texture.
Bake the Crust (First Side): Bake for 15–18 minutes until the crust is set and lightly golden around the edges.
Flip and Crisp: Carefully flip the crust over on the sheet pan and return to the oven for another 5–8 minutes. This dries and crisps the bottom, preventing a soggy crust.
Add Toppings: Remove from the oven and spread the passata or pizza sauce evenly over the crust. Top with shredded mozzarella and sprinkle with extra Italian seasoning and red pepper flakes.
Final Bake & Broil: Return to the oven and bake for 12–18 minutes until the cheese is melted and bubbling. Broil for 1–2 minutes at the end for golden brown spots if desired.
Rest and Slice: Allow the pizza to rest on the cutting board for 5 minutes so the crust firms up before slicing into pieces.