Preheat your oven to 400°F and line a large rimmed baking sheet with parchment paper.
Slice the chicken breast into even 1-inch strips and halve the cremini mushrooms.
In a large mixing bowl, whisk together the melted ghee, minced garlic, chopped thyme, rosemary, sea salt, and black pepper.
Add the chicken, mushrooms, and broccoli florets to the bowl and toss thoroughly until every piece is well-coated in the herb butter.
Spread the mixture onto the prepared baking sheet in a single layer, ensuring the ingredients are not overcrowded.
Roast for 18 to 20 minutes, or until the chicken is cooked through and the mushrooms are beautifully browned.
Remove from the oven and serve immediately, spooning any extra garlic-herb butter from the pan over the dish.