Step 1: Prepare the Eggplant Shells

1. Preheat your oven to 400°F (200°C).
2. Wash and dry the eggplants. Slice them in half lengthwise, right through the stem.
3. Using a small, sharp paring knife, carefully score around the inside perimeter of each eggplant half, leaving about a 1/2-inch border. This creates a guideline and prevents you from piercing the skin.
4. Next, score the inner flesh in a crisscross or diamond pattern, being careful not to cut all the way through the skin. This helps the eggplant cook more evenly.
5. Use a spoon (a grapefruit spoon works wonders here!) to gently scoop out the scored flesh, leaving a hollowed-out “boat” with about a 1/2-inch thick wall.
6. Roughly chop the scooped-out eggplant flesh and set it aside. You will use this in your filling.
7. Place the hollowed-out eggplant shells cut-side-up on a large, parchment-lined baking sheet. Drizzle them with 2 tablespoons of olive oil and sprinkle generously with coarse sea salt and black pepper.
8. Roast the eggplant shells for 20-25 minutes, or until they are just beginning to soften and turn golden brown at the edges. This pre-baking step is crucial for ensuring the final dish is tender and not watery.

Step 2: Create the Rich and Hearty Filling

1. While the eggplant shells are roasting, heat the remaining 1 tablespoon of olive oil in a large skillet or Dutch oven over medium-high heat.
2. Add the chopped yellow onion and sauté for 4-5 minutes until it becomes soft and translucent.
3. Add the minced garlic and cook for another minute until fragrant, stirring constantly to prevent it from burning.
4. Add the ground beef to the skillet. Use a wooden spoon to break it up and cook until it’s browned all over, about 5-7 minutes. Drain off any excess fat.
5. If using, pour in the red wine to deglaze the pan, scraping up any browned bits from the bottom. Let it simmer and reduce by about half, which should take 2-3 minutes.
6. Stir in the tomato paste and cook for 1 minute to deepen its flavor.
7. Add the can of diced tomatoes (with their juices), the chopped eggplant flesh you set aside earlier, the dried oregano, dried basil, and optional red pepper flakes. Stir everything together to combine.
8. Bring the mixture to a simmer, then reduce the heat to low, cover, and let it cook for 15 minutes. This allows the flavors to meld and the eggplant flesh to become tender.
9. Uncover the skillet and continue to simmer for another 5-10 minutes, or until the sauce has thickened nicely. You don’t want a watery filling.
10. Remove the skillet from the heat. Stir in the 1/4 cup of grated Parmesan cheese and half of the fresh parsley. Season generously with salt and black pepper to taste. The filling should be well-seasoned on its own.

Step 3: Stuff and Bake to Perfection

1. Remove the pre-baked eggplant shells from the oven. If any excess moisture has pooled inside them, carefully pat it dry with a paper towel.
2. Arrange the shells snugly in a 9×13 inch baking dish. This helps them stay upright.
3. Generously spoon the meat and vegetable filling into each eggplant shell, mounding it slightly on top.
4. In a small bowl, toss together the shredded mozzarella and the remaining 1/4 cup of grated Parmesan cheese.
5. Sprinkle the cheese mixture evenly over the top of each stuffed eggplant.
6. Bake, uncovered, at 400°F (200°C) for 15-20 minutes, or until the filling is heated through and the cheese on top is melted, bubbly, and beautifully golden brown.
7. Remove from the oven and let the stuffed eggplants rest for 5-10 minutes. This allows them to set up slightly, making them easier to serve and allowing the flavors to settle.
8. Garnish with the remaining fresh parsley before serving.