Creamy Bucatini With Spring Onions and Mint

Rich and creamy in texture, and full of sweet-savory onion flavor, this rather mild-looking pasta packs a wallop on the fork. The pistachios add color and crunch, but other nuts work nearly as well. And if you can’t get spring onions (that is, fresh bunches of onions with their greens still attached, available in late spring and early summer), you can substitute regular onions or a combination of alliums, such as sweet onions, scallions, ramps or leeks.

Ingredients

• Salt

• 1

  pound bucatini or thick spaghetti

• 3

  tablespoons unsalted butter

• 1

  pound spring onions, thinly sliced, including any nice greens (about 4 cups, see Tip)

• 1 ¼

  cups heavy cream

• 1

  large sprig fresh rosemary

• Large pinch of red-pepper flakes

• Freshly ground black pepper

• 1 ¼

  cup grated Pecorino Romano

• 1

  teaspoon finely grated lemon zest

• ¼

  cup chives, finely chopped, more for serving

• ⅓

  cup torn mint leaves, for serving

• Chopped pistachio, for serving (or use pine nuts or almonds)

Preparation

1. Bring a large pot of heavily salted water to a boil over high heat. Add pasta and cook until it is just shy of al dente, usually 2 minutes less than the package instructions. Reserve about 1 cup pasta water for the sauce (a coffee mug is good for this), then drain the pasta.
2. Meanwhile, in a large skillet, melt butter over medium-high heat. Add onions and cook, stirring occasionally, until golden brown at the edges and thoroughly soft, 12 to 15 minutes.
3. Add heavy cream, rosemary, 1/2 teaspoon salt, red-pepper flakes, and a few grinds black pepper to the pan, and bring to a simmer. Let cream reduce and thicken, 2 to 4 minutes.
4. Reduce heat to low and stir in Pecorino Romano until combined. Add the drained pasta and about 1/2 cup of the reserved pasta water. Toss well to coat the pasta. If the sauce is too thick, add pasta water by the tablespoon; if it’s too thin, let it bubble and reduce for a minute or so. Remove from heat and stir in lemon zest and chives. Taste and add more salt, if needed.
5. Serve in bowls, each topped with more chives, mint, a generous amount of black pepper and a sprinkle of pistachios.