Preheat oven to 375°F.
Bring a medium size cast iron skillet up to heat over medium high.
Season the thighs with salt and pepper. Add 2 tablespoons of ghee to the hot pan and add in the thighs skin side down, working in batches if you need to. Cook for 5-7 minutes or until golden brown and crispy. Flip and cook for another 2 minutes. Remove the par-cooked chicken to a plate.
Add the rosemary to the pan and sauté for 30 seconds. Next add in the fennel and cook until lightly golden and starts to soften, 2-3 minutes. Season with salt and pepper. Deglaze the pan with the vermouth, making sure to scrape up any brown bits from the bottom.
Lastly add in the mustard, stirring it into the sauce, followed by the halved potatoes and stock. Season with a little more salt and pepper. Add the chicken, skin side up, back into the pan nestling it down into the liquid.
Bake for 35-40 minutes or until the chicken is cooked through and the potatoes are tender.
Remove from oven and garnish with the fennel fronds. Serve family style.
Recipe Courtesy of Megan Mitchell