Preheat your oven to 400°F (200°C) and line a small baking sheet with parchment paper.
Clean and slice the cremini mushrooms, then toss them on the baking sheet with melted ghee, minced garlic, dried thyme, and half of the sea salt and black pepper.
Roast the mushrooms for 15-20 minutes until they are tender and have developed a deep golden-brown color.
While the mushrooms roast, season the chicken breast with the remaining sea salt and black pepper.
Heat a non-stick skillet over medium-high heat and sear the chicken for 6-7 minutes per side until the internal temperature reaches 165°F.
In a small mixing bowl, whisk together the plain Greek yogurt, lemon juice, and grated parmesan cheese until the mixture is smooth and creamy.
Once the mushrooms are done, remove them from the oven and immediately fold them into the yogurt mixture while still hot to create a warm, velvety sauce.
Slice the rested chicken breast into strips and plate them, generously spooning the creamy garlic butter mushrooms over the top.
Garnish with fresh chopped parsley and serve immediately.