Heat olive oil in a large skillet over medium heat.
Add minced garlic and sauté for 30 seconds until fragrant.
Add sliced mushrooms and cook until softened and lightly browned.
Stir in cauliflower florets and mix well.
Season with salt, black pepper, and Italian seasoning.
Cover the skillet and cook for 8–10 minutes, stirring occasionally.
Add butter and stir until melted and combined.
Cook uncovered for 2–3 minutes until cauliflower is tender.
Remove from heat and garnish with parsley and Parmesan cheese.
Serve warm as a main dish or side.