In a large skillet, heat 2 tbsp of the olive oil over medium-high heat. Add mushrooms and sauté 5 minutes, until lightly browned. Transfer to a bowl. Heat remaining 1 tbsp of the oil in a medium saucepan over medium heat. Add shallot and cook 3 minutes. Stir in farro and wine; cook 1 minute. Add broth, salt and pepper; bring to a simmer. Cover and simmer 35 to 40 minutes, until tender. Stir in sautéed mushrooms.
In a small bowl, combine pistachios, parsley, mint, lemon zest, oil, garlic and salt. Set aside.
Meanwhile, heat oil in same skillet over mediumhigh heat. Season salmon with salt and pepper and place in skillet, skin side down. Cook 3 minutes, turn and cook an additional 3 minutes.