1. Put the beans in a medium glass or stainless-steel bowl. Using a fork, mash the beans to a coarse puree. Stir in the vinegar, oil, thyme, salt, pepper, and 2 tablespoons of the parsley.
2. Put some of the prosciutto on each of the bruschetta and top with the bean mixture. Sprinkle the remaining 1/2 tablespoon parsley and the red onion over the beans.