Place the farro in a large pot and cover with cold water. Let soak for 15-20 minutes while you prep your other ingredients. Drain the farro and place back in pot. Cover with 2 quarts of water.
Bring to a boil. Reduce the heat and simmer, uncovered, for about 25 minutes; drain. The grains should be tender but still slightly chewy.
Meanwhile, heat 2 tablespoons of olive oil over medium-high heat in a large skillet. Sauté the garlic and shallot for 2 minutes or until fragrant (do not let brown). Add the mushrooms and thyme and saute for 5 to 7 minutes, or until the mushrooms are softened and beginning to brown. Season generously with salt and pepper.
Add the wine and let simmer for 2 to 3 minutes or until the wine evaporates. Stir in the cooked farro and turn off heat. Pour the mixture into a bowl and let cool slightly.
MAKE AHEAD: Cook the farro mushroom mixture a day or two in advance and keep in the refrigerator. Just before serving, heat the remaining tablespoon of olive oil in the same skillet and add the farro mushroom mixture. Sauté for a couple of minutes, stirring frequently, until the farro mushroom mixture is heated through. Season with additional salt and pepper (if needed) and garnish with extra thyme leaves.