Directions:
1. Prepare the caramelized onions. Coat an 8-inch cast-iron skillet or thick-bottomed sauté pan with 1 tablespoon olive oil. Heat the skillet on medium-high heat until oil begins to shimmer and add onion slices, stirring with a wooden spoon. Cook for 10 minutes, stir intermittently. Reduce heat to medium-low and stir in the balsamic vinegar.
2. Cook for 5 minutes. Remove from heat and set aside. Meanwhile, preheat oven to 400° F.
3. Cut the eggplant in half lengthwise into 8 strips roughly 2 inches wide and then cut strips widthwise into 8 sections. Place the eggplant pieces onto a parchment paper lined baking sheet. Brush the piece with 1 tablespoon olive oil. Place in oven and bake for 10 to 12 minutes or until golden brown and soft. Remove eggplant pieces, place in a bowl, add lemon juice and toss to coat each piece. Combine parsley, diced tomatoes, 1⁄8 cup feta in a small bowl. Set both aside.
4. Adjust oven to 350°F. In a food processor or blender, pulse lentils and mushrooms until texture is grainy and roughly combined. Scoop the mixture into a large mixing bowl. Stir in the pita crumbs, eggplant, onions, 1⁄4 cup feta, garlic, oregano, 1⁄8 cup olive oil and broth until evenly combined. Transfer the lentil loaf contents into a 9 x 5-inch nonstick loaf pan and smooth top with a spatula. Bake for 25 minutes, remove from oven and sprinkle nutmeg, and tomato, parsley and feta mix evenly over the top. Return to oven and bake for 5 more minutes. Remove and let loaf rest for 15 to 30 minutes or until it feels firm enough to slice.