Preheat the oven to 325°F. Cut the eggplants lengthwise into thin slices, spread them out on your work surface, and sprinkle with salt. Wait about 5 minutes and dab the moisture from the eggplants with paper towels. You can also cook the bucatini noodles.
Halve the slices again lengthwise and line the loaf pan with them in a crisscross pattern. Make sure to save some slices back for the "lid" later.
Cut off the tops and bottoms of the bell peppers and dice them into small pieces. Remove the core from the bell peppers so you're left with 3 ribbons.
Add the diced bell peppers, garlic, onion, and rosemary to a bowl, together with the ground beef, eggs, salt, and pepper, and mix well.
Spread about ⅔ of the ground beef mixture over the eggplant slices, with the edges coming up to the top of the loaf pan.
Place the 3 bell pepper ribbons next to each other in the pan with the openings facing up.
Lay the cooked bucatini noodles inside the bell pepper ribbons.
Mix the eggs and heavy cream and pour the mixture over the noodles.
Close the peppers over the noodles and spread the remaining ground beef mixture on top.
Arrange the remaining eggplant slices on top of the terrine and cook for 40 minutes.
