1) In a spice grinder, grind a handful of dried mushrooms for 25-30 seconds until they are powdered. Measure out a Tablespoon of the powder.
2) Use kitchen twine to tie together parsley and thyme sprigs with bay leaf.
3) Melt butter in a large, sturdy pot (dutch oven works well) over medium heat. Add leeks, carrots, celery, white wine and soy sauce, plus a big pinch of salt. Cook until liquid is evaporated and veggies are soft, about 10 minutes.
4) Add water, broth, barley, mushroom powder, herb bundle, and garlic. Increase heat and bring to a simmer. Reduce heat and simmer for 25 minutes, partially covered.
5) Add potatoes, turnips, and cabbage. Cook until tender, about 20 minutes.
6) Remove soup from heat and stir in peas and chopped parsley. Remove herb bundle. Season with salt and pepper.
Serve with crusty bread and lemon-thyme butter.