It's an easy gluten-free, vegetarian meal that's savory, juicy and bursting with flavor! Quick enough for a weekday, tasty enough for a weekend cookout.
Marinate portobellos: in a large bowl whisk olive oil, balsamic vinegar and garlic. Add cleaned portobello mushrooms and use a spoon or brush to toss and make sure they are generously coated.
After the portobello has cooked 5-7 minutes per side, flip the portobellos again (they will be stem side down now) and top with cheese, cover and let melt, approximately 1 minute.