Make the marinade/dressing. In a jar or bowl, whisk together olive oil, lemon zest and juice, garlic, oregano, thyme, Dijon, honey, salt, and pepper. Taste and adjust salt or lemon to your liking.
Marinate the chicken. Place the chicken in a zip-top bag or shallow dish.
Pour about half the dressing over it, turning to coat. Marinate for at least 20 minutes (up to 8 hours in the fridge). Reserve the remaining dressing for the salad.
Cook the chicken. Heat a grill pan or skillet over medium-high.
Lightly oil the surface. Cook chicken 5–6 minutes per side, or until the internal temperature reaches 165°F (74°C). Rest for 5 minutes, then slice.
Prep the base. While the chicken cooks, arrange your greens in a large bowl or platter.
Scatter cucumber, tomatoes, red onion, and bell pepper over the top.
Add the power players. Spoon on the quinoa or chickpeas, olives, and feta. Sprinkle with chopped herbs. If using avocado or nuts, add them now.
Dress and toss. Drizzle the reserved dressing over the salad.
Toss gently to coat the greens without crushing the vegetables. Add more salt, pepper, or lemon if needed.
Top with chicken and serve. Lay warm slices of chicken over the salad. Finish with a final squeeze of lemon and a pinch of oregano or sumac for brightness.