In a large skillet, melt the butter over medium heat.
Add the sliced mushrooms and sauté for about 5 minutes, or until they begin to soften and release their juices.
Stir in the minced garlic and dried thyme, cooking for an additional 1-2 minutes until fragrant.
Add the cauliflower florets to the skillet, stirring to combine. Season with salt and pepper.
Cover the skillet and cook for 8-10 minutes, stirring occasionally, until the cauliflower is tender.
Remove the lid and cook for another 2-3 minutes to allow any excess moisture to evaporate.
Garnish with fresh parsley before serving.