Place dried mushrooms in a dish and cover with ½ cup boiling water. Let sit for 15 minutes. Chop mushrooms and reserve liquid.
Divide the cremini mushrooms in half. Thinly slice one half and chop the other half into ¼ - ½-inch pieces and place in separate bowls. This creates different textures in the finished soup.
Heat 1 tbsp. olive oil in a large soup pot over medium-high heat. Add sliced mushrooms and cook, stirring, until softened. Remove mushrooms and set aside.
Add another tbsp. olive oil to the pan along with onions, carrots, celery, and chopped mushrooms. Cook and stir until all the vegetables are soft.
Add pearl barley, garlic, tomato paste, smoked paprika, chopped thyme, salt and pepper. Stir to coat everything in the tomato/spice mixture.
Add chopped rehydrated mushrooms and the liquid plus broth. Bring to a rolling boil. Reduce heat to a gentle simmer, cover and cook for 30 minutes.
Add in cooked, sliced mushrooms and parsley. Stir and taste. Adjust seasonings as necessary.
As it sits the barley will absorb the broth so it will thicken further. Feel free to add more broth to reach the consistency you like.