Preheat the oven to 400ºF.
Pour the juice from the marinated artichokes into a bowl. Slice the artichoke hearts into smaller pieces then add them to the bowl.
Add the quartered mushrooms, chopped tomatoes, Parmesan cheese and black pepper to the bowl. Stir thoroughly until the ingredients are well coated.
Slice the whole wheat baguette on the diagonal into ½” rounds and place on a baking sheet.
Toast the sliced bread in the oven for 3 minutes, then flip each piece over and toast an additional 3 minutes.
Remove the toasted bread from the oven and immediately rub with the clove of garlic (it works best to first cut a small tip off the garlic clove so that the oils will seep out).
Spoon the artichoke mixture onto the garlic-rubbed toasts and serve.