We think everyone should know how to make a beautiful pan sauce. It’s an exercise in building flavor and resourceful cooking, and everything is cooked in one pan, making clean-up a whole lot easier... on you. This version celebrates an unmistakable southern French flavor profile that will have you licking your plate.
Place one chicken breast in a plastic zip-top bag, removing as much air as possible as you seal it shut. Find a heavy, flat object to pound the chicken breast - meat mallet, rolling pin, or pan will all work - and pound the breast until it's an even thickness. Once you've got the chicken breast pounded to desired thickness, you can remove the chicken breast from the bag and reuse the bag for the remaining chicken.
Lightly salt and pepper each side of each chicken breast. Over medium-high heat, warm oil until it starts to ripple. Add chicken to pan and saute 3-4 minutes on each side until internal temperature reaches 165F. Once done, remove from pan to rest, loosely tented with foil to cover.
Over medium-high heat, in the pan you cooked the chicken, warm oil until it starts to ripple. Add shallots until they just start to turn translucent, stirring occasionally. Add mushrooms and saute until they are turning brown on the edges. Once shallots and mushrooms are cooked, add mustard and dried herbs, stirring to incorporate until fragrant, about 30 seconds.
Add water or stock to deglaze the pan, scraping the bottom of the pan to release any golden and crispy bits. When liquid comes back up to a simmer, add lemon mixture and allow sauce to reduce by half. (Reducing the sauce intensifies the flavor, as well as the saltiness, so don't add salt until sauce is reduced.)
Remove pan from heat and stir in butter and fresh herbs. Pour warm sauce over chicken and serve immediately.
If you don’t have Herbs de Provence in your spice cabinet, you can substitute an equal amount with a mix of dried thyme, dried parsley, dried basil, and or a pinch of lavender.