1. Clean **barley** and put to boil in a large pot of salted water. (If using pearled, boil for 30min; if using hulled, boil for ~1hr.)
2. Soak **porcini mushrooms** in a bowl of very hot water, just enough to cover them.
3. Saute the **onion** with some salt. When they’re translucent (~5min), add the **garlic**, **cremini mushrooms**, and more salt, and cook until the mushroom’s water is boiled out (~12min).
4. Remove now-rehydrated mushrooms from the water (reserving the water!) and rough chop. Add to the onion/mushroom mixture, along with a tsp of truffle oil. Cook for 5min.
5. When barley is done (do not drain!), add the onion/mushroom mixture, the **potatoes**, the **reserved mushroom water**, some more truffle oil, and a heavy pinch of salt. Cook for ~15min, until potatoes are tender.
6. Serve with dollop of sour cream and a few drops of truffle oil.