Make this Creamy Walnut Sauce in minutes by toasting walnuts and blending them with mascarpone and a handful of ingredients. Stir into pasta with a little butter and reserved cooking water for a delicious meal!
Toast the shelled walnuts in a 10-inch pan on the stove for 3-4 minutes over medium-high heat, stirring occasionally. The walnuts are ready when they are fragrant. Don't let them burn. Set the pan aside on a cool spot on the stove.
Grate the Parmesan and Romano cheeses, if needed. (I use my blender.)
Place a pasta pot filled ⅔ high with hot water on the stove over high heat. Add about a couple teaspoons of salt to the water and cover the pot.
While the water is heating, prepare the walnut sauce. Place the toasted walnuts, mascarpone, olive oil, Parmesan, Romano, garlic, basil, salt and pepper into your food processor or blender. Process until the sauce becomes a smooth paste, scraping down the sides as needed.
When the water is boiling, add the pasta and stir it in. Lower the heat a bit and continue cooking it until it's al dente.
While the pasta is cooking, scoop out a cup of the pasta water (I use my standard ladle and take two scoops) and place it in a pasta bowl near the stove.
Drain the pasta when it's cooked, setting it in a colander in the sink. Add two tablespoons of butter to the pot, then stir in the drained pasta, so it doesn't stick.
Add all of the walnut sauce to the pot, along with ½ cup of the reserved pasta water. Stir to combine with the pasta and add extra reserved water as needed, so the pasta is not dry.
Serve immediately with red pepper flakes and extra Parmesan. If you have any leftovers, stir in any remaining, reserved pasta water to the leftovers and store, covered, in the refrigerator for up to four days.
The leftover pasta will be dry, so you will need to add some butter or olive oil when reheating it.
You can use American cream cheese in place of mascarpone, but the walnut sauce will be less decadent. Mascarpone gives it a "wow" factor.
One clove of garlic is plenty here. Using more overpowers the sauce, since the garlic is raw.
It's best to enjoy this dish immediately, since the leftovers will become dry. If you know you'll only need half a pound of pasta, use half of the sauce and store the leftover sauce in a covered container in the refrigerator for up to four days (make sure the date on the mascarpone has not expired). Then, you can cook fresh pasta to go with it the next time, adding butter and some reserved pasta water.