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 slice them into halves or quarters if they are large.
Dice the chicken breast into uniform 1-inch cubes to ensure even cooking.
Place the chicken and mushrooms on the prepared baking sheet, then drizzle with the extra virgin olive oil.
Season the mixture with sea salt and black pepper, tossing well to coat every piece.
Spread the ingredients in a single layer, ensuring they aren't crowded so they roast rather than steam.
Roast in the oven for 15 minutes.
While the chicken roasts, mince the garlic cloves and finely chop the fresh thyme.
In a small bowl, combine the ghee, minced garlic, and thyme. Microwave for 15 seconds or until the ghee is melted and fragrant.
Remove the baking sheet from the oven, drizzle the garlic ghee mixture over the chicken and mushrooms, and toss gently.
Return the pan to the oven for an additional 5-7 minutes until the chicken is cooked through and the mushrooms are golden brown.
Remove from the oven, drizzle with fresh lemon juice, and garnish with chopped fresh parsley before serving.