Pat the chicken breast dry with paper towels and season both sides evenly with dried oregano, garlic powder, sea salt, and black pepper.
Heat the extra virgin olive oil in a medium non-stick skillet over medium-high heat.
Place the chicken in the skillet and cook for 5 to 7 minutes per side, or until the internal temperature reaches 165 degrees Fahrenheit and the exterior is golden brown.
While the chicken cooks, dice the cucumber and halve the cherry tomatoes.
In a large serving bowl, create a base with the fresh baby spinach and the warm, cooked quinoa.
Remove the chicken from the pan, let it rest for 2 minutes, then slice it into thin strips.
Arrange the sliced chicken, cucumbers, and tomatoes over the quinoa and spinach.
Drizzle the entire bowl with fresh lemon juice and serve immediately.