Prepare the Eggplant:

1. Preheat oven to 375°F (190°C) and line a baking sheet with parchment paper.
2. Lay out eggplant slices in a single layer.
3. Mix olive oil, smashed garlic, and oregano in a small bowl. Brush the mixture onto both sides of the eggplant slices.
4. Roast for 20-25 minutes, flipping halfway through, until golden and tender.

2. Sauté the Vegetables:

1. Heat olive oil in a skillet over medium heat.
2. Add the reserved garlic and cook for 1 minute until fragrant.
3. Toss in bell peppers, onion, salt, and black pepper. Stir well.
4. Sprinkle crushed red pepper and Italian seasoning. Cook for 6-8 minutes until tender and slightly caramelized.

3. Assemble the Eggplant Parmesan:

1. Preheat oven to 400°F (200°C).
2. Spread 1 cup marinara sauce evenly on the bottom of a 9×13-inch baking dish.
3. Layer half the roasted eggplant slices over the sauce.
4. Top with half the sautéed veggies, followed by a sprinkle of breadcrumbs and half the mozzarella cheese.
5. Repeat layers: marinara, eggplant, veggies, breadcrumbs, and mozzarella.
6. Finish with remaining breadcrumbs and Parmesan cheese.

4. Bake the Dish:

1. Cover the dish with aluminum foil and bake for 20 minutes.
2. Remove foil and bake for an additional 10-15 minutes until cheese is bubbly and golden.

5. Garnish and Serve:

1. Let the dish rest for 5 minutes before serving.
2. Sprinkle with fresh basil or parsley and serve warm with a salad or crusty bread.