In a large bowl, combine chicken cubes with 1 tbsp olive oil, lemon juice, oregano, thyme, garlic powder, salt, and pepper. Toss well to coat evenly. Let the chicken marinate at room temperature for at least 15 minutes while you prepare other ingredients, or cover and refrigerate for up to 30 minutes for deeper flavor.

Rinse the quinoa thoroughly under cold running water in a fine-mesh sieve. In a medium saucepan, combine the rinsed quinoa and vegetable broth. Bring to a boil over high heat, then immediately reduce the heat to low, cover the saucepan tightly, and simmer for 15 minutes, or until all the liquid is absorbed and the quinoa is fluffy. Remove from heat and let it stand, covered, for another 5 minutes, then fluff with a fork.

If using a skillet: Heat a large skillet over medium-high heat. Add the marinated chicken in a single layer (cook in batches if necessary to avoid overcrowding, which can steam the chicken instead of browning it). Cook for 5-7 minutes, turning occasionally, until the chicken is cooked through and lightly browned on all sides, reaching an internal temperature of 165°F (74°C). If using an air fryer: Preheat air fryer to 400°F (200°C). Arrange chicken in a single layer in the air fryer basket (cook in batches if needed). Air fry for 10-12 minutes, shaking the basket halfway through, until cooked through and lightly crisped.

While the chicken and quinoa are cooking, prepare the vinaigrette. In a small bowl, whisk together the 2 tbsp extra virgin olive oil, lemon juice, chopped fresh dill, minced garlic, Dijon mustard, salt, and pepper until well combined and emulsified.

Divide the cooked quinoa evenly among 4 individual meal prep containers. Top each portion of quinoa with the cooked lemon-herb chicken. Arrange the cherry tomatoes, diced cucumber, thinly sliced red onion, and Kalamata olives neatly around the chicken and quinoa.

Drizzle each bowl with a generous amount of the lemon-dill vinaigrette. Garnish with fresh chopped parsley and crumbled feta cheese, if using. For meal prep, seal the containers and refrigerate.