Meatballs:

1. Soak the dried mushrooms in cold water for one hour or until soft. Drain and squeeze dry. Remove stem. Chop in food processor until fine but not paste.
2. Preheat oven to 375F.
3. Use your hands to combine the meatballs ingredients in a large mixing bowl. Do not over mix.
4. Use cooking spray on 2 lipped cookie sheets.
5. Use a cookie scoop to measure out the mix, then roll into balls and put onto the sheets, almost touching.
6. Place sheets on 2 shelves in the middle of the oven.
7. Cook for 30 minutes until 165F internal temperature and lightly browned, swapping sheets half way through.

Gravy:

1. Heat a deep pot over high heat. Add oil then shiitake. Cook stirring constantly 3-4 minutes or until a little smoky and browned.
2. Turn heat down to medium and add the onion. Cook another 3-4 minutes until onions are soft but not browned.
3. Add garlic, saute 1 minute.
4. Sprinkle flour over in 2-3 batches, stirring each time.
5. Cook another few minutes without browning.
6. Gradually add stocks and sake, whisking constantly.
7. Add mirin and soy sauce.
8. Raise heat to high until simmering, whisking frequently.
9. Lower heat to a low simmer and cook 10 minutes until thoroughly thickened.

Service:

1. Move meatballs to a full size deep hotel pan in several batches. Ladle some gravy over each layer, saving 1/3 gravy to put on top.
2. Cover and keep warm (> 140F) until service.