Servings: 4

4 small boneless, skinless chicken breasts (about 1¾ pounds) 4 small boneless, skinless chicken breasts (about 1¾ pounds)
1½ teaspoons kosher salt 1½ teaspoons kosher salt
2 tablespoons salted butter 2 tablespoons salted butter
2 tablespoons extra-virgin olive oil 2 tablespoons extra-virgin olive oil
2 large shallots, finely chopped 2 large shallots, finely chopped
3 garlic cloves, grated 3 garlic cloves, grated
½ cup dry white wine ½ cup dry white wine
¾ cup heavy cream ¾ cup heavy cream
¾ cup chicken stock ¾ cup chicken stock
1 teaspoon fresh thyme leaves 1 teaspoon fresh thyme leaves
1 bay leaf 1 bay leaf
1 teaspoon Dijon mustard 1 teaspoon Dijon mustard
1 tablespoon whole grain mustard 1 tablespoon whole grain mustard
2 tablespoons chopped fresh tarragon 2 tablespoons chopped fresh tarragon
¼ teaspoon freshly cracked black pepper ¼ teaspoon freshly cracked black pepper
1 tablespoon cornstarch 1 tablespoon cornstarch

Pat the chicken dry and season all over with 1 teaspoon of the salt.
Heat the butter and oil in a large skillet over medium heat. Once the oil is glistening, add the chicken and cook until golden brown, about 5 minutes per side. Transfer the chicken to a plate.
To the same skillet, add the shallots and cook, stirring, until tender, about 4 minutes. Stir in the garlic until fragrant, about 30 seconds. Stir in the wine and cook, scraping up any brown bits as you stir, until the liquid has been reduced by half, about 4 minutes. Stir in the heavy cream, chicken stock, thyme, bay leaf, Dijon, whole grain mustard, 1 tablespoon of the tarragon, pepper and the remaining ½ teaspoon salt. Reduce the heat to low and simmer for about 10 minutes.
Return the chicken and any collected juices to the skillet. Increase the heat to high and return the mixture to a simmer, then reduce the heat to medium low. Cook until the internal temperature of the chicken reaches 165°F on an instant-read thermometer, about 15 minutes more.
In a small bowl, combine the cornstarch with 2 tablespoons of cool water. Transfer the chicken to a plate, then stir the cornstarch slurry into the sauce. Cook the sauce until thickened, about 3 minutes. Nestle in the chicken and top with the pepper and remaining 1 tablespoon of the tarragon.