Preparation Cook pasta in boiling salted water in a 5- to 6-quart heavy pot according to package directions. Four minutes before pasta is done, add peas. Reserve 1/2 cup cooking water, then drain pasta with peas in a colander. While pasta cooks, heat butter in a 12-inch heavy skillet over moderately high heat until foam subsides, then sauté mushrooms with salt and pepper, stirring occasionally, until any liquid they give off is evaporated and mushrooms are golden, about 4 minutes. Add cream and reserved cooking water and bring to a simmer. Reduce heat to low and stir in cheeses until sauce is fairly smooth. Add hot pasta and peas and stir until coated with sauce. Serve sprinkled with chives.
Preparation Cook pasta in boiling salted water in a 5- to 6-quart heavy pot according to package directions. Four minutes before pasta is done, add peas. Reserve 1/2 cup cooking water, then drain pasta with peas in a colander. While pasta cooks, heat butter in a 12-inch heavy skillet over moderately high heat until foam subsides, then sauté mushrooms with salt and pepper, stirring occasionally, until any liquid they give off is evaporated and mushrooms are golden, about 4 minutes. Add cream and reserved cooking water and bring to a simmer. Reduce heat to low and stir in cheeses until sauce is fairly smooth. Add hot pasta and peas and stir until coated with sauce. Serve sprinkled with chives.