Vegan Portobello Mushroom Burgers

Marinate Overnight (optional for optimal flavor)
2 Clean the mushrooms by removing the stem and scraping out the gills using a spoon. Removing the gills is optional but I recommend it. I save the stems to cook separately or chop up to use in a different recipe.
3 Brush the mushrooms with sauce marinade of choice (and oil if using), I used about 1/4 cup for each mushroom. Allow to marinate overnight or at least an hour for optimal flavor.
If baking:
6 Put into a baking dish, and bake at 350 F/ 175 C for about 15 minutes.
7  Flip over and bake another 15 minutes.
If grilling:
10 Add to a hot grill pan and cook for 3-5 minutes on each side, until nice and browned.
11 If using an outside grill, cook for 3-5 minutes over a medium flame and flip over, making sure to watch for burning.
Serve with toppings of your choice!