Cook quinoa in chicken broth according to directions listed on package, season lightly with salt and pepper. Let cool slightly once cooked and toss with 1 Tbsp olive oil and 1 tsp lemon zest.
Meanwhile heat 2 Tbsp olive oil in a large skillet over medium-high heat. Add garlic and saute 10 seconds, then add zucchini and corn and saute, tossing only occasionally so veggies lightly brown, about 8 minutes.
Pour quinoa into a large bowl (or individual bowls and just divide all ingredients among bowls), top with grilled chicken, zucchini and corn mixture, green onions and feta cheese. Drizzle lemon juice over top and toss mixture. Serve warm.