Prep the mushrooms and leeks. Add 1 ounce of dried porcini mushrooms to a bowl and cover with 2 cups of boiling water. Let it sit for 30 minutes, then strain through a cheesecloth. Reserve the liquid and the mushrooms; throw away the cheesecloth.
Add the remaining dried porcini mushrooms (1/2 ounce) to a blender and blend until they turn into a dust-like consistency. Set aside.
Soak sliced leeks in water and then strain and pat dry.
Make the soup. To a large pot, add olive oil, onions, leeks, salt and pepper. Saute over medium heat until veggies are tender, about 5 minutes.
Add potatoes, cannellini beans (with liquid), porcini mushroom “juice”, rehydrated porcini mushrooms, 2 tbsp of the “porcini dust”, veggie broth, thyme, and oregano.
Bring to a boil, then reduce to a simmer and let simmer until the potatoes are VERY tender.
Remove the oregano stalks and blend. I love my immersion blender, BUT you will get the best results if you blend this soup in a blender.
Make the porcini salt. Add all of the porcini salt ingredients to a small bowl and mix well.
Serve. Pour into a giant soup bowl and top with parsley and porcini salt!!