In a large skillet, heat 2 tablespoons of the olive oil. Add the shallots, season with salt and cook over moderate heat until softened, about 4 minutes. Add the remaining 1 tablespoon of olive oil and the radicchio to the skillet and toss well. Cover and cook over moderate heat, stirring a few times, until the radicchio is tender, about 5 minutes. Season with salt. Transfer the radicchio to a bowl. Top with the <em>ricotta salata</em> shavings, season with pepper and serve.