Prepare the Grain Foundation: Rinse the farro under cold water. In a medium saucepan, bring 3 cups of water to a boil. Add the farro, reduce heat to a simmer, and cook according to package directions, typically 15-20 minutes, until tender but still chewy. Drain any excess water and set aside.
Emulsify the Vinaigrette: While the farro cooks, prepare the vinaigrette. In a small bowl, whisk together the extra virgin olive oil, red wine vinegar, lemon zest, lemon juice, minced garlic, dried oregano, and sumac until well combined. Set aside to allow the flavors to meld.
Create the Yogurt Sauce: In a separate small bowl, combine the non-fat Greek yogurt, grated cucumber, chopped fresh dill, minced garlic, and lemon juice. Stir until smooth. Refrigerate until ready to serve.
Assemble the Sheet Pan: Preheat your oven to 400°F (200°C). On a large baking sheet, toss the cherry tomatoes and sliced red onion with 1 tablespoon of olive oil. In a third small bowl, mix the smoked paprika, garlic powder, oregano, onion powder, and black pepper. Pat the salmon fillets dry and rub the spice blend evenly over all sides. Nestle the seasoned salmon fillets among the vegetables on the sheet pan.
Roast to Perfection: Transfer the sheet pan to the preheated oven and roast for 12-15 minutes, or until the salmon is cooked through and flakes easily with a fork. The tomatoes should be blistered and soft.
Compose the Bowls: To assemble, divide the cooked farro evenly among four bowls. Top with a large handful of fresh arugula. Arrange a salmon fillet in each bowl alongside the roasted tomatoes and onions. Evenly distribute the diced cucumber, rinsed chickpeas, and rinsed Kalamata olives. Drizzle generously with the Lemon-Herb Vinaigrette and finish with a dollop of the Cooling Dill-Yogurt Sauce.