Preheat the oven to 350 degrees F.

Remove the stems from the caps, and cut into 2 inch pieces.

Mix the olive oil with all ingredients (except balsamic vinegar)

in an ovenproof casserole dish. (I have a 'deep' baking sheet that works well)

Add the mushrooms, and mix well, ensuring all mushrooms are 'coated'

Bake for about 35 minutes.

Remove from the heat, and drizzle with the balsamic vinegar.