Heat oven to 200°F. Set a wire rack over a rimmed baking sheet and place in oven. Heat waffle iron per directions.
In a large bowl, whisk together chickpea flour, baking soda, and ¼ tsp salt. In a small bowl, whisk together yogurt and eggs. Stir wet ingredients into dry ingredients. Fold in scallions, spinach, red pepper, pecorino, and ¼ tsp pepper.
Lightly coat waffle iron (like this one from Cuisinart) with nonstick cooking spray and, in batches, drop ¼ cup batter into each section of iron and cook until golden brown, 4 to 5 minutes. Transfer to oven and keep warm. Repeat with remaining batter.
