Coat portabella's with EVOO. Roast them under 400 degrees for 30 minutes, or until very soft & tender.
Cut into slices.
Put however much garlic inside of 1.5T of oil, saute for a minute. Add 2.5T of Basalmic vinegar, bring to a boil until it thickens/emulsifies (usually 2-3 minutes).
Toss mushroom slices with sauce.
Top with (my choices) lemon pepper, salt, and fresh parsley.