Step 1

In a small bowl, whisk together the ricotta, chives and ¼ teaspoon each salt and pepper. Set aside. In a large pot, bring 4 quarts of water to a boil. Add the pasta and 2 tablespoons salt and cook until al dente. Reserve 2 cups of the cooking water, drain the pasta and return it to the pot. Add 1 tablespoon of the butter and ½ cup of the reserved cooking water; toss to coat.

Step 2

Meanwhile, in a 12-inch skillet over medium-high, heat 2 tablespoons of the butter until foaming. Add the mushrooms, shallots and ¼ teaspoon each salt and pepper. Cook, stirring, until the mushrooms have released their moisture and are well browned, about 10 minutes. Pour in the wine, scrape up any browned bits and simmer until almost evaporated, about 5 minutes.

Step 3

Pour in the remaining 1½ cups reserved cooking water, bring to a simmer and cook over medium-high until the mixture has thickened, about 10 minutes. Off heat, stir in the miso and remaining 1 tablespoon butter. Taste and season with salt and pepper.

Step 4

Add the tarragon to the pasta and toss, then transfer to a serving bowl. Spoon the mushroom mixture over the pasta. Serve dolloped with the ricotta mixture and drizzled with olive oil.