What to serve on meatless Mondays? Look no further, this is it. It's ready in a jiffy, is bright, rich and delicious.
1 lb. rigatoni pasta
Kosher salt
8 T. unsalted butter, cut into pieces, divided
1 Meyer lemon, very thinly sliced into rounds, seeds removed*
2 c. reserved pasta cooking water, divided
1 oz. Parmesan or Parmigiano-Reggiano cheese, finely grated, plus more for serving
freshly ground black pepper
Cook rigatoni in a large pot of well salted boiling water, stirring occasionally, until al dente, about 2 minutes less than package directions.The pasta will finish cooking in the sauce.
Meanwhile, heat 4 T. butter in a large Dutch oven or other heavy pot over medium until melted; add lemon rounds; cook, stirring often, until softened and bottom of pot is browned in spots, 5–7 minutes. Using tongs, transfer one-third of lemon rounds to a plate; set aside.
Just before pasta is al dente, reserve 2 c. of the pasta cooking water. Add 1 1/2 c. of the pasta cooking water to the butter sauce. (It will thicken when the remaining ingredients are added.) Add remaining butter, a piece at a time, whisking until each piece is incorporated before adding more, until the sauce is emulsified and creamy.
Drain pasta; add to the sauce. Cook, stirring often and adding 1 oz. Parmesan cheese, a little at a time. Once all of the cheese is added, continue to cook, stirring, until cheese is melted and sauce is creamy and clings to pasta, about 3 minutes. If the sauce looks too thick, add pasta cooking water 1–2 T. at a time to thin it. (saucier is good as it will thicken as it cools). Remove from heat. Season with pepper; toss.
Serve topped with lemon rounds and more cheese, if desired.
4 servings.
*Before slicing the lemon into rounds, you might consider putting the lemon in boiling water for 2 minutes to soften the bitterness.