Step 1

Place a large cast iron skillet into the oven then preheat oven to 400 degrees. If you don't have a cast iron skillet you can use a pie pan or casserole dish - do not preheat either of those.

Step 2

Add butter and garlic to a small dish then microwave until melted, 30 seconds. Trim ends off mushrooms with a small knife then place cap side down in skillet or baking dish. Drizzle each cap with garlic butter, taking care to get garlic on the mushroom vs on the skillet or baking dish, then season tops with salt and pepper. Roast for 25-30 minutes, or until tender, basting mushrooms with butter in the bottom of the skillet halfway through.