for the marinara sauce: heat the olive oil in a large pot over medium-high heat.
add the onions and garlic and sauté until the onions are translucent, about 10 minutes. Add the celery, carrots, and 1/4 teaspoon each salt and pepper.
sauté until all the vegetables are soft, about 10 more minutes. Add the tomatoes and bay leaf, and simmer uncovered over low heat until the sauce thickens, about 1 hour. Remove and discard the bay leaf.
season the sauce with more salt and pepper to taste.
for the pasta dish: bring a large pot of salted water to a boil over high heat.
add the pasta and cook, stirring occasionally, until tender but still firm to the bite, about 8 minutes. Drain. Meanwhile, heat 3 tablespoons of the oil from the sun-dried tomato jar in a large, heavy skillet over medium heat.
add the diced eggplants and cook, stirring occasionally, until golden, about 6 minutes.
add the sun-dried tomatoes and the marinara sauce and cook until heated through, about 5 minutes. add the cooked pasta to the tomato sauce and stir to combine. Turn off the heat and add the mozzarella cheese, basil, salt, and pepper.
season with more salt and pepper to taste. Transfer to shallow pasta bowls, top with parmesan cheese and serve.