1. Place dried mushrooms in a medium bowl; cover with boiling water. Let stand 30 minutes or until tender; drain. Coarsely chop mushrooms.
2. Bring Mushroom Stock to a simmer in a small saucepan (do not boil). Keep stock warm over low heat.
3. Heat a Dutch oven over medium heat. Add oil to pan; swirl to coat. Add farro and onion; cook 5 minutes, stirring occasionally. Add garlic; cook 1 minute, stirring constantly. Add rehydrated mushrooms, cremini mushrooms, and 1/2 teaspoon salt; sauté 5 minutes or until cremini mushrooms are tender, stirring occasionally. Add wine and thyme; cook until liquid almost evaporates.
4. Add 1/2 cup stock to farro mixture; cook over medium heat 4 minutes or until the liquid is nearly absorbed, stirring occasionally. Add 4 1/2 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).
5. Add remaining 1/4 teaspoon salt, 1/2 cup stock, cheese, parsley, and pepper; stir until cheese melts.
Wine note: I like the thought of serving a sparkling wine with Farro Risotto with Mushrooms--the bubbles match the texture of the grain. Prosecco has become a popular aperitif, but this Soligo Prosecco ($12) is fuller bodied than most, so it stands up well to food. With its vibrant stone fruit flavors, it contrasts pleasantly with the earthy character of the mushrooms that dominate this dish. --Gary Vaynerchuck