Preheat the oven to 350 degrees F.
Arrange the eggplant slices on a baking sheet; sprinkle with salt and drizzle with olive oil. Bake for 15 minutes.
Bring a pot of salted water to a boil. Set up a bowl of ice water alongside. Add the broccoli rabe to the pot and cook for a few minutes. Transfer to the ice bath. Drain, pat dry and chop finely.
Combine the broccoli rabe, ricotta, mozzarella, Parmesan and egg in a food processor; process until smooth.
Spread a thin layer of the filling onto each slice of eggplant. Roll the slices up tightly and place, seam-side down, in a 9-by-13-inch baking dish. Bake for 10 minutes.
Meanwhile, sweat the onions in some olive oil in a medium pan, about 5 minutes. Add the vegetable stock, crushed red pepper, tomatoes, garlic and oregano. Bring to a boil, lower the heat and simmer for 15 minutes.
In a bowl, toss the arugula with the red wine vinegar and some olive oil. Season with salt.
Place a large spoonful of tomato sauce on each plate, top with an eggplant rollatini and some arugula salad. Sprinkle with basil and Parmesan.