Sauteed trumpet mushrooms look like scallops, but are much more forgiving to cook, and a hell of a lot cheaper. I love them in this pasta--it feels surprisingly elegant--but you could make the mushrooms on their own for salads or grain bowls. I use white pasta here since whole wheat's earthy flavor can overwhelm the mushrooms.
Bring a large pot of water to a rolling boil. Salt aggressively and add the linguine. Cook until 3 minutes before the package says the pasta will be done. Use a liquid measuring cup to scoop out 1 cup (240 milliliters) of the pasta water, set the water aside, then drain the pasta.
Meanwhile, heat the oil in a large skillet over medium-high heat. Add the mushrooms and season with 1 teaspoon each salt and pepper. Cook the mushrooms, stirring a few times, until golden brown on both sides, 10 to 14 minutes. You want them to brown nicely, so avoid stirring too much.
Add the cooked pasta to the pan with 3/4 cup (180 milliliters) of the reserved pasta water and cook, stirring constantly, until the pasta is cooked through, 1 to 3 minutes more. Add the remaining 1/4 cup (60 milliliters) pasta water if the pasta is too dry.
Remove from the heat, stir in the chives, lemon juice and butter, and season with 1 teaspoon salt and 1/4 teaspoon pepper. Serve hot.