How to Make It
In a large skillet, heat 3 tablespoons of the olive oil. Add the eggplant and cook over moderately high heat, stirring occasionally, until browned all over, about 10 minutes. Add the garlic, season with salt and cook, stirring, until fragrant, about 1 minute longer. Remove from the heat.
In a medium saucepan, bring the chicken stock to a simmer. In a large saucepan, heat the remaining 1 tablespoon of olive oil. Add the onion and cook over moderate heat until softened, about 5 minutes. Add all but 1/4 cup of the chopped tomatoes and cook, stirring, until softened, about 3 minutes. Add the rice and cook, stirring, until thoroughly coated, about 2 minutes.
Add 1 cup of the hot chicken stock and cook, stirring, until the stock is nearly absorbed, about 3 minutes. Continue adding the hot stock 1 cup at a time and stirring until it is absorbed between additions. The risotto is done when the rice is al dente and suspended in a creamy liquid, about 25 minutes total.
Remove the risotto from the heat. Stir in the butter, then stir in the ricotta salata and Parmigiano-Reggiano cheeses. Stir in the eggplant and basil along with the remaining 1/4 cup of tomatoes. Season with salt and pepper and transfer to bowls. Serve right away.