In a large and shallow baking dish, whisk all the marinade ingredients together. Taste and add more seasoning if desired (*note: the flavors will be concentrated).
Add the mushrooms to the dish and liberally brush the marinade on all sides. You can also spoon it on. Let it sit for 10-20 minutes, flipping and brushing again midway through the marinating time.
Heat a Grill, Grill Pan OR Skillet over medium-high heat. When fully heated, brush with oil and place the mushrooms on top (they should sizzle when they hit the pan). Don't move them once they are in the pan, just gently press down with a spatula or tongs. Give them a minimum of 4-5 minutes so they sear. Flip over and sear the other side, adding more oil if needed (you can also brush on more marinade). Grill until browned and tender about 4-5 minutes. Enjoy!
Use a dry, slightly damp paper towel or a soft brush to clean each mushroom. They are like sponges and will absorb a lot of water which can make them soggy.
It's very important to heat the pan/grill thoroughly before adding the mushrooms or they won't sear properly.
Don't overcrowd the pan or the mushrooms will steam and cause a lot of moisture.
SERVING IDEAS: serve with fries, roasted potatoes, salad, macaroni salad, grilled vegetables or potato salad. You can also serve it in a burger bun with roasted peppers, vegan pesto and grilled red onion. *The nutritional information includes the full amount of marinade.