This simple pasta side dish pairs nicely with roasted or grilled meat or chicken.
In a large skillet, combine scallions, 1/2 teaspoon salt, 1/4 teaspoon pepper, and 1/2 cup water; cook over medium-high heat, stirring often, until scallions wilt and pan is almost dry, 8 to 10 minutes.
Add cream; stir to coat. Cover; reduce heat to low, and cook at a bare simmer (cream will separate if boiled), stirring occasionally, until scallions are tender, 20 minutes.
Meanwhile, cook pasta in a large pot of boiling salted water until al dente, according to package instructions. Reserve 1/4 cup pasta water; drain pasta, and return to pot.
Toss pasta with warm sauce and reserved pasta water; season with salt and pepper. Serve immediately.