Grilled portobello mushroom sandwich is a delicious and healthy vegetarian option that is popular in Portugal. To make a grilled portobello mushroom sandwich, start by cleaning and removing the stems from the mushrooms. Then, mix together some olive oil, minced garlic, chopped herbs (such as rosemary, thyme, or oregano), salt, and pepper. Brush the mixture over both sides of the mushrooms, and let them marinate for at least 30 minutes. Next, heat up a grill or grill pan over medium-high heat. Grill the mushrooms for about 5-7 minutes on each side, until they are tender and slightly charred. While the mushrooms are grilling, slice some crusty bread (such as ciabatta or sourdough) and toast it until it’s lightly golden. To assemble the sandwich, spread some hummus, pesto, or mustard on…