¾ teaspoon kosher salt, plus more for salting pasta water
⅓ cup heavy cream
8 ounces lump crab meat
1 generous handful (1 ½ cups lightly packed) arugula
Bring a large pot of generously salted water to a boil (the water should taste like the ocean). Cook the pasta until still a bit firm, 1 minute less than the box timing for al dente. Set up a large bowl of ice water. Once the pasta is done, reserve ½ cup pasta cooking water, then drain the pasta and drop it into the ice water (this is called shocking) for 30 seconds, then drain again.
Melt the butter in a 12-inch saute pan over medium heat. Add garlic, shallots and ¼ teaspoon salt and saute until soft and fragrant, 2 to 3 minutes. Take the pan off the heat, add the wine, then return to the heat and reduce the liquid by half, 2 to 3 minutes.
Reduce the heat to low, then whisk in the cream and the remaining 1/2 teaspoon salt. Add the pasta, crab, and arugula to pan and toss to coat, adding a bit of the reserved pasta cooking water to loosen the sauce if you want, then cook until the arugula has just wilted, 1 to 2 minutes. Season with more salt to taste and enjoy!