1. Combine the bruschetta ingredients and place in the refrigerator until you are finished preparing the mushrooms.
2. Preheat your oven to 375F/190C
3. Wash the Portobello mushrooms gently and pat them dry on a towel. Carefully remove the stems and gills. Place on a baking sheet.
4. Combine the marinade ingredients and brush onto both sides of the mushrooms.
5. Place the mushrooms in the oven with the hollowed part facing up. Bake for 10-15 minutes.
6. On a stovetop on medium-high heat, heat the vegan butter and olive oil in a frying pan.
7. When the butter has melted, add the garlic and fry for less than a minute. Make sure they do not brown.
8. Add in the breadcrumbs, nutritional yeast, parsley, salt and vegan parmesan. Fry for about 3-5 minutes, or until lightly browned.
9. Remove the mushrooms from the oven. They will have rendered off a lot of juice. Grab each mushroom gently with a pair of kitchen tongs and reserve the juice for later. Place the mushrooms back in the oven, flipping the mushrooms over with the top side up. Bake for 10-15 minutes.
10. Remove the mushrooms from the oven, and stuff them each with about 2 tbsp of the breadcrumb stuffing. Top the mushrooms with the reserved juice and place back in the oven for another 10 minutes.
11. When the mushrooms have finished cooking, remove them from the oven and top them with the bruschetta topping. Garnish and enjoy!