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 in half; trim the woody ends off the asparagus spears.
Cut the chicken breast into bite-sized 1-inch chunks to ensure even roasting and maximum surface area for seasoning.
In a small bowl, whisk together the melted ghee, minced garlic, chopped thyme, and chopped rosemary.
Place the chicken, mushrooms, and asparagus on the prepared baking sheet and drizzle the garlic-herb ghee over the top.
Season the mixture with sea salt and black pepper, then toss everything thoroughly with your hands to coat each piece.
Spread the ingredients into a single layer and roast for 18-22 minutes until the chicken is cooked through and the mushrooms are tender.
Remove the pan from the oven and finish with a bright squeeze of fresh lemon juice before serving.