In a large pot, cook barley for 40 minutes in 3 cups of lightly salted water. Drain the excess water. At the same time, in another pot of water, cook the potatoes for 15 minutes or until they are tender.
Preheat oven to 180°C.
In a large skillet with oil, add onions, white button and wild mushrooms. Salt. Add carrots and celery. Cook 10 min.
Dissolve miso in soy sauce and add mustard and spices.
Add barley, potatoes, beans, and miso soy mixture to the vegetables in the skillet. Mix well. Cook for 5 minutes, add a little water if the mixture becomes too dry.
On a floured surface, roll out the two balls of pastry dough and line a 23cm (9") pie plate with one sheet of dough (or one pie shell). Spread the mixture of mushrooms, vegetables, and barley. Cover with the second sheet of dough (or pie shell) and make an slit in the middle.
Bake 50min.
Serve with a homemade ketchup or with our Smoked Slippery Jack Mushroom Mustard.