How to Make It
In a large pot of boiling salted water, cook the penne until al dente. Drain, reserving 3/4 cup of the cooking water.
Meanwhile, in a large, deep skillet, heat the olive oil until shimmering. Add the onion, season with salt and pepper and cook over moderately high heat until softened and just beginning to brown, about 5 minutes. Add the bell peppers, capers and crushed red pepper and cook, stirring occasionally, until the peppers are softened and lightly browned in spots, about 10 minutes. Stir in the vinegar and cook until nearly evaporated, about 2 minutes. Add the tomato sauce and cook for 5 minutes.
Add the penne and the reserved cooking water to the sauce, season with salt and pepper and simmer, stirring, until thickened, about 2 minutes. Stir in the basil. Transfer the pasta to bowls, sprinkle with the Pecorino and serve.