Remove the stem + gills from a portobello mushroom, then cook hollowed side up. You can use a variety of produce or meat for the 'stuffing'- my recipe uses a mix of kale, sun-dried tomatoes, onions and olives for a Tuscan-inspired dish. Once cooked, simply scoop the filling into the mushrooms then eat as is, or sprinkle with some vegan cheese and cook once more until the tops are lightly toasted.