Step 1: Mix all marinade ingredients in a bowl or plastic bag. The best route is likely a platic bag so you can flip it, but I just poured the marinade over the mushrooms in a shallow pie pan.
Step 2: Place in the refrigerator and marinate at least 6 hours, preferably overnight. They are like little sponges and will soak up all those tasty flavors. After a few hours they get soft, don’t panic.
Step 3: Put on an oiled grill or fry in a pan. You could also roast in the oven at 400 for 15-20 minutes. I cooked mine for 5-10 minutes each side on the stove top, then sliced into strips.
With some avocado, cooked rice, roma tomatoes, and feta cheese, I had the perfect vegetarian burrito! Portobellos also have 1 gram of protein per ounce, plus the avocado and cheese. It will very filling without feeling heavy. These mushrooms will be a staple part of my summer cooking repertoire for sure.