This is a more hands-off approach to the Italian classic. Crispy chicken is topped with a savory sauce full of umami from the mushrooms with rich flavor due to a reduction of marsala and stock. The rich flavors are rounded out with bright fresh green onions and tarragon.
Preheat oven to 425ºF and oil a rimmed baking sheet with olive oil.
Season the chicken well with salt and pepper. Place it skin side up on the prepared baking sheet. Bake at 425ºF for 45-50 minutes, or until the chicken is brown and crisp (it should measure 165ºF when the internal temperature is taken).
After 20 minutes of baking the chicken, add the sliced mushrooms to the pan and toss with any drippings. Return to the oven and continue to bake.
When the chicken is crispy, remove from oven and transfer chicken to a plate. Add the marsala and stock and stir to scrape up any browned bits. Transfer to a pan, add the green onions, and heat over high heat until liquid is reduced by half and the alcohol is gone. Whisk in butter off heat and pour the sauce over the chicken. Serve immediately.