Place the chicken breast in a small pot and cover with water; bring to a light simmer and poach for 12-15 minutes until fully cooked.
While the chicken poaches, mince the garlic and finely chop the fresh dill and chives.
In a medium mixing bowl, whisk together the Greek yogurt, lemon juice, lemon zest, minced garlic, dill, and chives until smooth.
Remove the chicken from the water, let it cool slightly, and use two forks to shred the meat into thin strands.
Fold the shredded chicken into the yogurt mixture until every piece is well coated.
Heat the olive oil in a skillet over medium heat, add the spinach, and sauté for 1-2 minutes until just wilted; season with half of the salt and pepper.
Warm the pre-cooked quinoa and place it in a bowl, top with the wilted spinach and the creamy herb chicken.
Finish with the remaining sea salt and black pepper before serving.