Spinach Feta Brownies

Preheat the oven to 375 degrees F (190 degrees C). Use about 1 tablespoon of the melted butter to grease a 7x11-inch baking dish.

Heat olive oil in a non-stick skillet over medium heat. Add onions to the hot oil and cook, stirring frequently, until onions are soft and beginning to turn clear, 3 to 4 minutes. Remove skillet from heat and add spinach. Stir spinach into the onions, breaking up any large clumps.

Stir together flour, baking powder, and salt in a large bowl.

Combine milk and eggs in a small bowl, whisking until milk and eggs are fully incorporated. Drizzle in remaining melted butter, while continuing to stir. Add to flour mixture and stir until there are no lumps.

Fold in spinach mixture, French herbs, feta cheese, and mozzarella. Do not over-mix. Pour into the prepared dish, using a spatula to smooth and level the surface. Sprinkle grated Pecorino Romano evenly over the top.

Bake in the center of the preheated oven until the top is browned, 40 to 45 minutes. Test for doneness with a wooden pick inserted into the middle. The dish is done, if the pick comes out clean.

Allow to cool for 10 to 15 minutes.

Cut into 18 brownies and garnish with fresh parsley to serve.