Add the eggplant pieces to a mixing bowl and season with 1 tsp salt, tossing to ensure all pieces are well coated
Set aside for 20 minutes (this helps to draw out moisture and remove bitterness)
Preheat oven to 400°F and line a large baking sheet with parchment paper
Drain and rinse eggplant well to remove excess salt then pat very dry with paper towels or a clean tea towel
Transfer to the prepared baking sheet and season with ½ tsp black pepper; add the red pepper and press flat then toss everything with 1 tbsp olive oil
Roast for 30 minutes or until lightly charred then remove the eggplant from the baking sheet and return the red pepper to the oven; broil for 1 minute or until the skin is charred and blistered then set the oven back to 400℉ (see Note 1)
While the eggplant and pepper are roasting, bring a large pot of salted water to a boil and cook pasta until al dente; set aside, reserving ½ cup pasta water
Once the red pepper has cooled, peel and remove the skin and dice
Heat a large pot over medium-low heat and add the remaining 2 tbsp of olive oil (you can even wipe and reuse the pot you cooked the pasta in to save dishes)
Add the onion and celery and sauté for 3-4 minutes, then add the chili flakes and garlic and sauté for 30 seconds or until fragrant
Add the tomatoes, Parmesan rind and olives and simmer for 10-15 minutes or until tomatoes have started to break down and the consistency is saucy (see Note 2)
Stir in the roasted eggplant and roasted red pepper along with the capers, honey, red wine vinegar, the remaining ½ tsp black pepper and salt to taste
Remove the Parmesan rind and discard, then stir in the cooked pasta, pasta water and 2 tbsp fresh parsley, then transfer to a large broiler safe baking dish
Top with the cheeses and bake for 7-8 minutes or until melted, then broil for 1-2 minutes until bubbly and golden
Top with the remaining tbsp of parsley and serve