mixed mushroom and tarragon gravy

prep time: 45 minutes

total time: 1 hour 45 minutes (includes mushroom-soaking time)

makes: about 7 cups

ingredients

• 2 ounces dried porcini mushrooms
• 2 cups boiling water
• 1/4 cup (1/2 stick) unsalted butter
• 1 large shallot, chopped (about 1/2 cup)
• 3 large garlic cloves, chopped
• 1/2 pound fresh crimini (baby bella) mushrooms, stemmed, caps sliced
• 1/2 pound fresh shiitake mushrooms, stemmed, caps sliced
• 1 teaspoon chopped fresh thyme
• 1 teaspoon chopped fresh sage
• 1 cup dry vermouth or dry white wine
• 4 1/4 cups low-salt chicken broth, divided
• 1/2 cup sour cream
• 5 teaspoons cornstarch
• 1 1/2 teaspoons chopped fresh tarragon

the technique: make ahead

on thanksgiving, do-aheads are key. this super-savory gravy can be made a day ahead. all you have to do before serving is heat it up and stir in some tarragon. no last-minute pan-scraping and reducing required.

preparation

• place dried porcini in large bowl. pour 2 cups boiling water over. let stand until soft, stirring occasionally, about 1 hour. using slotted spoon, transfer porcini to small bowl. cool porcini, then chop. pour porcini soaking liquid into medium bowl, leaving sediment behind.
• melt butter in large skillet over medium-high heat. add shallot and garlic. stir 15 seconds. add fresh mushrooms, thyme, and sage. sauté until mushrooms are tender, 6 to 7 minutes. transfer mushrooms to bowl. add vermouth to skillet; boil 3 minutes, scraping up browned bits. add 4 cups stock, fresh-mushroom mixture, porcini, and porcini liquid. boil 10 minutes. whisk in sour cream. stir 1/4 cup stock and cornstarch in bowl to dissolve; mix into gravy. cook until gravy coats spoon, about 5 minutes. season with salt and pepper. do ahead: can be made 1 day ahead. cool, cover, and chill. rewarm before continuing.
• whisk tarragon into gravy and serve.