For a hearty and meaty veggie sandwich, try a roasted Portobello mushroom sandwich. Marinate the Portobello mushrooms in a mixture of balsamic vinegar, soy sauce, garlic, and herbs. Roast the mushrooms until tender and juicy. Assemble your sandwich with the roasted mushrooms, caramelized onions, melted Swiss cheese, and a spread of Dijon mustard. This sandwich is a great option for mushroom lovers and is packed with umami flavors.
