In a large saucepan, bring 6 cups salted water to a boil. Add barley, reduce heat to a simmer, and cook until barley is tender, 30-40 minutes; drain.
Heat oil in a medium saucepan over medium heat. Add leeks, 2 Tbsp. water and season with salt. Cover and cook until leeks have wilted, about 5 minutes. Stir in garlic and cook 30 seconds. Stir in barley, lemon zest and cook for 5 minutes over medium-low heat.
Stir in chives and top with grated Romano cheese.