Clean the fresh mushrooms by lightly brushing off any dirt. Peel off any tough outer skins of the mushroom caps and discard. (Tip: Mushrooms absorb water quickly. If you rinse them heavily when cleaning, they can absorb too much water and dilute the flavor of the soup.)
Using a Dutch oven or large stock pot, heat the olive oil over medium heat. Add the onion, celery, garlic and mushrooms. Cover pot and cook over medium-low heat for 6-7 minutes, or until onions have softened slightly. (Note: Don't be alarmed by the volume of mushrooms. They will cook down quite a bit very quickly!)
Add sherry and cook over medium heat (uncovered) for 15 minutes, or until mushrooms are soft.
Place the dried porcini mushrooms in a food processor or mini-chopper. Pulse until finely ground.
Add dried mushrooms, vegetable stock, spinach and orca beans. Bring to a boil. Reduce heat to medium-low and simmer for 30 minutes.
Add the barley and simmer for another 30 minutes.
Garnish with fresh chopped parsley before serving.
Feel free to substitute other varieties of mushrooms based on what is available.I recommend using sherry from a wine store rather than the sherry that is sold in grocery stores. It's not much more expensive, and it makes a huge difference in flavor!