Heat oil in a large pan over high heat. Add onion and garlic and a pinch of salt and cook until starting to soften. Add the eggplant and more salt. Toss and cook until eggplant has some color.
Add the crushed tomatoes, season them with salt, and basil and simmer for 10 minutes. The eggplant should retain its shape, but be very soft.
Cook pasta 1 minute short of al dente and add to the pan with the condiment. If the sauce is too tight, splash with the pasta cooking water to adjust. Grate ricotta salata into the pan and toss until melted and the sauce takes on a creamy consistency.
Take the pan off the heat and add mint leaves. Toss and pour into a serving bowl. Add a drizzle of your best quality extra-virgin olive oil, a sprinkling of red pepper flakes, and a handful of more ricotta salata, and serve.