These Greek stuffed portobello mushrooms are a delicious and healthy vegetarian dish. The portobello mushrooms are filled with a flavorful mixture of spinach, feta cheese, and Mediterranean spices. Baked to perfection, these mushrooms are tender and juicy, with a savory and cheesy filling. They make a great appetizer or main course, and are perfect for a Mediterranean-inspired meal. Serve them with a side of Greek salad or roasted vegetables for a complete and satisfying meal.