Combine all the ingredients for the shrimp in a large bowl and marinate in the fridge for 20 minutes. Heat grill to medium-high. Remove shrimp from marinade and cook until opaque and cooked through, about 2 to 3 minutes per side.
In a large bowl combine quinoa, cucumber, tomatoes, parsley, feta cheese, and garbanzo beans. In a small bowl, whisk together olive oil, red wine vinegar and lemon juice. Pour vinaigrette over salad and toss well to combine. Add salt and pepper, to taste. Layer shrimp over salad. Garnish with avocado and serve.