Cook quinoa: Bring broth to a boil in a medium heavy pot. Rinse quinoa under cold water and drain well. Cook over low heat, covered, for 25 minutes. Turn off heat and let rest, covered, for 5 minutes. Use a fork to note any fluff.
For the shrimp: While the quinoa is cooking, combine 2 teaspoons olive oil, half the lemon juice, half the lemon zest, oregano, parsley, garlic, chile, salt, and pepper in a small bowl and mix well. Add the shrimp.
Heat in a grill or heavy skillet over high heat. When's gets very hot, with more oil over and the pour on shrimp. Cook 2 to 3 minutes on each side.
Divide the vegetables into 4 large serving bowls on one half of the bowl.
Place half of the quinoa in the other half and top with shrimp, chickpeas, tomatoes and onions.
Drizzle each salad with 1 teaspoon of the remaining olive oil, salt, pepper, red chili flakes and sprinkle with the remaining lemon juice.