If you want the bread to stay crunchy then remove it from pan before cooking the mushrooms and beans. Add it back in right before serving, it's good both ways.
Put the beans and mushrooms into a strainer while cooking the bread to get as much water out as possible.
I'm thinking this would also taste good with some fresh rosemary or thyme added in. Maybe even a splash of soy or worcestershire sauce!
I'm going to experiment with different mushrooms and breads, endless possibilities! Tell me what you did differently if you try this recipe!