Preheat oven to 425℉.
Bring a large, shallow 10-inch cast iron pan or Dutch oven up to heat over medium high.
While the pan heats up, cut the thighs into 1 1/2-inch pieces and season liberally with salt and pepper.
Once the pan is up to heat pour in the ghee and add the chicken in an even layer, working in batches if needed. Cook for 2-3 minutes, turning halfway through around so they brown evenly. Remove the par-cooked chicken with a slotted spoon or tongs to a plate.
Turn the heat down to medium and add in the onion, garlic and sage, sauté for 2-3 minutes or until fragrant and the onions have begun to soften. Deglaze the pan with the Vermouth, scraping up any brown bits that may have formed.
Next add in the chard and cook for 3-4 minutes or until it has begun to wilt down. Next add in the potato and stock. Stir together and season liberally with salt and pepper. Once everything comes up to a simmer add in the mascarpone and parmesan cheese and mix. Add the chicken back in, stir and remove from heat.
Lay the defrosted phyllo on a baking sheet and cover with a damp towel so it doesn’t dry out while you’re working. Place 1 sheet on a clean cutting board and brush/dab with some of the melted butter. Crumple the sheet up like you would with a piece of paper and place on top of the chicken mixture. Continue doing this with the remaining sheets covering the entire pan, overlapping when necessary. Drizzle any remaining butter on top and sprinkle with flaked sea salt.
Place in the oven and bake for 10 minutes. Turn the oven down to 375℉ and bake for another 20-25 minutes or until bubbly and the top is golden brown. Remove and let cool for 5-10 minutes before serving. If the mixture under the crust looks a little loose you can pop it on the stove on medium heat and cook for 5-10 minutes to help reduce some of the liquid.
Recipe Courtesy of Megan Mitchell