This nutty, Thai twist on pasta is pretty and delicious.
In a blender, pulse the oil, 3/4 cup scallions, 1/3 cup pistachios, the chopped cilantro, curry paste, lime zest and juice, and garlic until a chunky pesto forms. Season the pistachio pesto with salt and pepper.
Bring a large pot of water to a boil. Salt the boiling water and add the pasta. Cook until al dente. Reserve 1 cup of the cooking water and drain the pasta. Return the pasta and 1/2 cup of the cooking water to the pot. Add the pistachio pesto and the peas. Cook over medium-high heat, stirring constantly, until heated through, about 3 minutes; thin the sauce with a splash or two more of the cooking water, if needed. Season the pasta with salt and pepper.
Divide the pasta among shallow bowls. Top with the remaining pistachios, scallions, and cilantro sprigs.