Dice the eggplants and place them in a bowl with salted water for about 15 minutes to remove any bitterness. Wash and deseed the bell peppers, then cut them into bite-sized pieces.
Heat a generous drizzle of olive oil in a large skillet over medium heat and sauté the peppers until tender.
Meanwhile, drain and thoroughly pat the eggplant cubes dry. Once the peppers are cooked, transfer them to a plate. In the same skillet, fry the eggplant cubes until golden and tender, then set them aside with the peppers.
Remove the sausage meat from its casings and crumble it into the skillet. Brown the sausage thoroughly, breaking it apart with a wooden spoon.
Return the cooked peppers and eggplant to the pan with the sausage. Season with salt and pepper to taste, pour in the tomato passata, and add fresh basil. Simmer together over low heat for about 5 minutes.
In the meantime, bring a large pot of salted water to a rolling boil. Add the penne and cook until al dente according to package directions.
Drain the pasta, add it directly to the skillet with the sauce, and toss over medium heat for a minute to coat evenly before serving.
