In a large bowl, combine the chicken pieces with olive oil, lemon juice, minced garlic, oregano, dill, salt, and pepper. Toss to coat evenly and let marinate for at least 30 minutes in the refrigerator, or up to 4 hours for deeper flavor.

While the chicken marinates, rinse the quinoa thoroughly under cold water. In a medium saucepan, combine the rinsed quinoa and water or chicken broth. Bring to a boil, then reduce heat to low, cover, and simmer for 15 minutes or until the liquid is absorbed.

Remove the quinoa from heat and let it stand covered for 5 minutes. Fluff with a fork and stir in olive oil, lemon juice, and chopped parsley. Season with salt and pepper to taste.

Whisk together olive oil, lemon juice, red wine vinegar, minced garlic, dried oregano, fresh dill, salt, and pepper in a small bowl until well combined. Set aside to let flavors meld.

Heat a large skillet over medium-high heat. Add the marinated chicken in a single layer, working in batches if necessary to avoid crowding. Cook, stirring occasionally, until golden brown and cooked through to 165°F, about 6 to 8 minutes.

Divide the lemony quinoa among four bowls. Top with the cooked chicken, diced cucumber, halved cherry tomatoes, sliced red onion, kalamata olives, and a dollop of hummus. Drizzle with the lemon-herb vinaigrette and sprinkle with crumbled feta, fresh dill, and parsley.