Ingredients
 1/2 oz (10 g)  cup dried porcini mushrooms
 1/2 cup  boiling water
 1 tbsp each:  butter and olive oil
 1  onion, chopped (about 1 cup)
 3 cloves  garlic, minced (about 1 tbsp)
 1/4 tsp each:  dried rosemary and thyme
 4 to 5 cups   white mushrooms, thinly sliced
 1/4 cup  sherry
 1 tbsp  fresh lemon juice
 1 tsp  lemon zest
 6 cups   chicken or vegetable stock
 1/2 cup  pearl barley
1/2 cup  carrots, diced
1/4 cup  celery, diced
1  bay leaf
salt and pepper to taste
1/4  freshly chopped parsley chopped spring onions and
lemon zest for garnish 

Directions
Soak porcini mushrooms in boiling water for 15 minutes. Strain and reserve the liquid. Finely chop mushrooms, discarding rough pieces. Set aside. Heat butter and oil in a large saute pan or soup pot and saute onion until pale golden. Add garlic, rosemary, thyme and a pinch of salt and pepper. Add porcini and white mushrooms and their liquid, and saute over medium-high heat until mushrooms are brown and liquid has evaporated. Add sherry, lemon juice and zest, and reduce until pan is nearly dry. Add stock, barley, carrots, celery and bay leaf to mushroom mixture and simmer uncovered until barley is cooked, about 35 to 40 minutes. Season with salt and pepper and stir in chopped parsley. Serve garnished with spring onions and a few curls of lemon zest.
 
Tip: To make this a strictly vegetarian soup, substitute an equal amount of vegetable stock for chicken stock.

Source:   www.canadianhomeandcountry.com