In a heavy medium saucepan, heat oil over medium heat. Add barley and cook, stirring frequently, for 10 minutes. The barley should start to brown and give off an aroma.
Add shallots, and cook for 2 minutes. Add mushrooms, and cook until wilted, 2 to 3 minutes. Add stock and salt. Bring to a boil; then turn down heat to a bare simmer. Cover, and cook for 45 minutes, or until liquid is absorbed.
Stir well, season with pepper and more salt, if needed, and serve immediately.