Grilled Portabella Mushroom Burger

Here's a great recipe for Meatless Monday or really any day of the week... Portabella mushrooms make for a great meaty substitute when you're craving a burger but not the meat. Topped with all your favorite traditional burger toppings, you'll hardly know it's a veggie burger! Marinate and grill these jumbo mushroom caps until they're nice and tender,...