Tarragon Mushroom Cheese Sauce with Chicken

I used a recipe that I found on the Food & Wine website as the basis for the sauce.  I just used regular white mushrooms. I used boneless, skinless thighs instead of chicken breasts. And, the Food & Wine recipe does not call for Gruyère like this recipe does.

Ingredients
1 8 oz package of white mushrooms (I used pre-sliced)
1 tablespoon extra virgin olive oil
8-10 skinless, boneless chicken thighs or chicken breast - your choice
Salt and freshly ground pepper
2 tablespoons unsalted butter
1/2 cup dry white wine
1/2 cup chicken stock or low-sodium broth
1/2 cup heavy cream
1 tablespoon coarsely chopped tarragon
1 teaspoon fresh lemon juice
1 teaspoon lemon zest
1/4 cup grated Gruyère cheese

Method
1. Heat a large, deep sautée pan over medium high heat. Season chicken thighs with salt and pepper and add them to the pan. They should sizzle right away. Use tongs to open up the thighs and flatten them out. Sautée for about 4 minutes each side. Remove them from pan to a plate.
2. Add butter and mushrooms to the pan and sautée mushrooms until they just start to release their liquid, about 4 minutes.
3. Add white wine and simmer until reduced to just a couple of tablespoons, about 3 minutes.
4. Add chicken stock and simmer until reduced by 2/3, about 6 minutes.
5. Add the heavy cream and the tarragon and simmer until the sauce has thickened, about 4 minutes. Add the lemon juice and lemon zest and blend well. Add the grated Gruyère and stir constantly until melted and blended in. Season with salt and pepper.
6. Return chicken to the pan. (While the chicken was sitting, it sweat out a lot of juices. I did not add these back into the sauce because I felt I had gotten the balance of sauce flavors just right, but I imagine you could add that juice back in to good effect). Stir to coat chicken and simmer until heated through, about 3 minutes.