Preheat the oven to 375°F (190°C).

In a large skillet, heat the olive oil over medium heat. Add the chopped onions and sauté for 2-3 minutes, until translucent.

Add the minced garlic, red pepper flakes, and dried basil. Stir for 1-2 minutes, until fragrant.

Add the crushed tomatoes and salt and pepper to taste. Bring the sauce to a simmer and let it cook for 15-20 minutes, until thickened.

Meanwhile, prepare the eggplant. Sprinkle salt over the eggplant slices and let them sit for 10-15 minutes to remove excess moisture. Pat dry with a paper towel.

Set up a breading station with the flour, beaten eggs, and seasoned bread crumbs in separate bowls.

Dip each eggplant slice into the flour, then the beaten eggs, and then the seasoned bread crumbs. Make sure each slice is coated evenly.

Heat vegetable oil in a large skillet over medium heat. Fry the eggplant slices for 3-4 minutes on each side, until golden brown. Drain on paper towels.

In a 9×13 inch baking dish, spread a thin layer of marinara sauce on the bottom. Add a layer of fried eggplant slices, followed by a layer of shredded mozzarella cheese and grated parmesan cheese. Repeat the layers until all the eggplant slices are used up, ending with a layer of cheese.

Cover the baking dish with foil and bake for 25-30 minutes, until the cheese is melted and bubbly. Remove the foil and bake for an additional 5-10 minutes, until the cheese is golden brown.

Let the Eggplant Parmesan cool for a few minutes before serving.