1cupstarchy cooking water from pasta (2 standard ladles)
½cupgrated Pecorino Romano cheese
1pinchred pepper flakes(optional)
Instructions
Grate the Pecorino if needed. Peel and slice three cloves of garlic into ⅛-inch thick pieces and set them aside.
Fill a 6-quart pasta pot ⅔ full with hot water. Add one teaspoon of salt, cover and heat it on high to bring it to a boil. (Note that you'll use the same pot of boiling water to first blanche the rapini, then cook the pasta.)
While the pot is heating up, clean the rapini. Rinse it and cut off and discard the bottom four inches of thick stems. Cut the remaining rapini into two-inch pieces.
When the water is boiling, add the rapini and boil it for two minutes. Use a slotted spoon to remove the blanched broccoli rabe to a salad spinner or colander with a pan underneath it. (Keep the pot of water boiling.)
Add the pasta to the pot of boiling water and stir briefly. Cook the penne according to the al dente instructions on the package, stirring occasionally so the pasta doesn't stick. (You can work on the next step of the recipe while it's cooking.) When the pasta has a couple of minutes left to cook, scoop out one cup (two standard ladles) of the cooking water and place it in a bowl. After the pasta is done and you've saved some of the cooking water, drain the pasta in a colander in the sink. The cooked pasta can sit in the drainer until you're finished making the rapini.
While the pasta is cooking, heat five tablespoons of olive oil in a 12-inch nonstick skillet over medium-high heat. Add the garlic and cook it for a minute or so.
Drain the blanched rapini well, ideally using a salad spinner. (Otherwise use a colander.) Add the drained rapini to the skillet. Stir in ½ teaspoon of salt and ⅓ teaspoon of pepper. Cook the rapini for five minutes.
Lower the heat under the skillet and add the cooked, drained pasta to the pan of rapini. Pour in one ladle (½ cup) of reserved starchy cooking water and stir to combine. Add in a little more of the reserved water if the pasta seems dry. Stir in the Pecorino. Turn off the heat and add a pinch of red pepper flakes if desired. Serve with extra grated Pecorino or Parmesan, if you like.
Store leftovers in a sealed container in the refrigerator for up to four days.
Notes
Rapini is also known as "broccoli rabe." If you can't find it, you can substitute broccolini.