in a small saucepan, bring vegetable stock to a simmer (do not boil). Keep stock warm over low heat.
Heat a large saucepan over medium heat. Add oil to pan; swirl to coat. Add the shallots and garlic and cook over moderate heat, stirring until softened, about 2 minutes. Add the farro and cook, stirring for 5 minutes. Add the mushrooms and 1/2 teaspoon salt; sauté 5 minutes or until mushrooms are tender, stirring occasionally. Add wine and rosemary; cook until liquid almost evaporates.
Add 1 cup stock to farro mixture; cook over medium heat 4 minutes or until the liquid is nearly absorbed, stirring occasionally. Add 5 cups stock, 1/2 cup at a time, stirring occasionally until each portion of stock is absorbed before adding the next (about 40 minutes total).
Add remaining 1/4 teaspoon salt, cheese and pepper; stir until cheese melts.