Vegetarian Focaccia

Preheat the oven to 425°F (220°C). If using frozen dough, thaw it according to package directions; if making fresh dough, prepare it and let it rise until doubled in size.

Heat a skillet over medium heat and sauté the sliced mushrooms until they release their moisture and begin to brown, about 5-7 minutes. Season lightly with salt and set aside to cool.

In a large bowl, combine the cooked spinach, ricotta cheese, egg white, fresh parsley, and cooled mushrooms. Stir until the mixture is well blended and uniform.

Stretch or roll the focaccia dough to fit a lightly oiled 9x13-inch baking sheet, pressing gently to create an even thickness of about ½ inch.

Spread the spinach and mushroom ricotta mixture evenly over the dough, leaving a ½-inch border around the edges. Distribute the mozzarella cheese evenly over the top.

Bake in the preheated oven until the focaccia is golden brown and the cheese is melted, about 25-30 minutes.

Remove from the oven and let cool for 5 minutes before slicing and serving.