Marinate the chicken: In a bowl, combine olive oil, lemon juice, garlic, oregano, cumin, smoked paprika, salt, and pepper.
Add chicken and coat well. Let it rest for at least 20–30 minutes, or up to 8 hours in the fridge.
Make the yogurt sauce: Stir together Greek yogurt, lemon juice, olive oil, grated garlic, dill or parsley, salt, and pepper. Adjust lemon and salt to taste.
Chill until ready to use.
Prep your base: If using cauliflower rice, sauté in a skillet with a little olive oil and a pinch of salt for 3–5 minutes until just tender. If using quinoa, cook according to package instructions and fluff with a fork.
Cook the chicken: Heat a grill pan or skillet over medium-high. Cook chicken 4–6 minutes per side, depending on thickness, until juices run clear and it reaches 165°F (74°C).
Rest 5 minutes, then slice.
Prep the veggies: Halve tomatoes, dice cucumber, slice red onion, and wash and dry your greens. Pat olives dry to avoid watering down the bowl.
Assemble the bowls: Add cauliflower rice or quinoa to the bottom. Top with greens, chicken slices, tomatoes, cucumber, onion, and olives.
Sprinkle with feta.
Finish with sauce: Spoon the lemon-garlic yogurt sauce over the top. Add fresh herbs and a squeeze of lemon if you like.
Season and serve: Taste and add a pinch of salt, pepper, or a dash of sumac. Serve immediately.