In a large skillet over medium heat, melt the butter. Add the onion, carrot, and celery and saute until soft, 7-8 minutes.
Add garlic, cauliflower, and mushrooms and season with salt and pepper. Cook for 8-10 minutes or until tender.
Add parsley, rosemary, and sage; stir until thoroughly mixed. Pour the broth over mixture and cover with a lid. Cook until tender and all he liquid is absorbed, this should take about 15 minutes.