Preheat your oven to 400°F (200°C) and line a large rimmed baking sheet with parchment paper.
Clean the cremini mushrooms with a damp cloth and cut them into halves; slice the chicken breast into uniform 1-inch bite-sized pieces.
Place the chicken and mushrooms on the prepared baking sheet, then drizzle with the extra virgin olive oil and season with sea salt and black pepper.
Toss everything together until evenly coated and spread into a single layer, ensuring the chicken and mushrooms aren't overcrowded.
Roast in the oven for 15 minutes.
While the pan is roasting, melt the ghee in a small bowl and whisk in the minced garlic and fresh thyme leaves.
Remove the pan from the oven, drizzle the garlic-ghee mixture over the chicken and mushrooms, and toss gently to combine.
Return the pan to the oven and roast for an additional 5 to 7 minutes until the chicken is cooked through and the mushrooms are golden brown and tender.
Garnish with freshly chopped parsley and serve immediately while hot.