Preheat your oven to 425 degrees f. and line a large sheet pan with parchment paper.
In a large bowl, toss the cauliflower florets with 1 Tablespoon of oil, sea salt, and black pepper until nicely coated.
Spread the cauliflower onto the prepared sheet pan and roast for 20-25 minutes, or until it starts to lightly brown. Stir a few times during roasting.
In the meantime, place your mushrooms in a large baking dish and drizzle with the remaining tablespoon of oil.
Place your mushrooms into the oven (simultaneously while your cauliflower is roasting in a separate pan) and roast for around 20 minutes, stirring twice while baking.
Once the mushrooms are done, remove from the oven and add in the garlic, roasted cauliflower florets and sprinkle with parmesan cheese.
Return to the oven for 10 more minutes or just until nicely melted.
Garnish with fresh parsley.