Whisk together the olive oil, lemon zest, lemon juice, honey, garlic powder, oregano, basil, salt, pepper, and red pepper flakes.
Pound the chicken breasts to an even ½-inch thickness, then place them in a bowl or ziplock bag with the marinade and turn to coat.
Marinate for at least 30 minutes, up to several hours.
Combine all the tzatziki ingredients in a bowl and set aside.
Cook the rice or quinoa and prep the vegetables — shred the lettuce, halve the tomatoes, dice the cucumber, and slice the red onion.
Air fryer: preheat to 380°F and cook the chicken 7 minutes per side, until the internal temperature reaches 165°F.
Skillet: heat oil or butter over medium-low heat and cook the chicken 7–8 minutes per side, until golden and 165°F internally.
Rest the chicken for 5 minutes, then slice.
Assemble the bowls with rice, lettuce, tomatoes, cucumber, red onion, and feta. Top with the sliced chicken and a spoonful of tzatziki. Drizzle with olive oil and lemon juice if desired.