Step 1
Preheat oven to 400 degrees F (200 degrees C).
Step 2
Season chicken on all sides with salt and ground black pepper.
Step 3
Heat olive oil over medium-high heat in an ovenproof skillet. Place chicken skin-side down in skillet and cook until browned about 5 minutes.
Step 4
Turn chicken over; stir mushrooms with a pinch of salt into skillet. Increase heat to high; cook stirring mushrooms occasionally until mushrooms shrink slightly about 5 minutes.
Step 5
Transfer skillet to the preheated oven and cook until chicken is no longer pink in the center and the juices run clear 15 to 20 minutes. An instant-read thermometer inserted into the center should read 165 degrees F (74 degrees C). Transfer chicken breasts to a plate and loosely tent with foil; set aside.
Step 6
Set skillet on the stovetop over medium-high heat; cook and stir mushrooms until brown bits start to form on the bottom of the pan about 5 minutes. Pour water into the skillet and bring to a boil while scraping the browned bits off of the bottom of the pan. Cook until water is reduced by half about 2 minutes. Remove from heat.
Step 7
Stir in any accumulated juices from the chicken into the skillet. Stir butter into mushroom mixture stirring constantly until butter is completely melted and incorporated.
Step 8
Season with salt and pepper. Spoon mushroom sauce over chicken and serve.