Marinate the Chicken: In a bowl, whisk olive oil, lemon juice, garlic, oregano, salt, and pepper. Add chicken and marinate for at least 20 minutes.
Cook the Chicken: Grill or pan-sear over medium-high heat for 5–6 minutes per side until fully cooked. Let rest, then slice into strips.
Roast the Peppers: Preheat oven to 400°F. Toss diced peppers with olive oil, salt, and pepper. Roast for 18–20 minutes until tender and slightly charred.
Make the Salad: In a bowl, combine cherry tomatoes, cucumber, red onion, parsley, lemon juice, olive oil, feta, salt, and pepper. Mix well.
Prepare the Tzatziki: In a bowl, mix Greek yogurt, grated cucumber, garlic, lemon juice, dill, salt, and pepper until smooth.
Assemble the Bowl: Add cucumber tomato salad and roasted peppers to a bowl. Top with sliced chicken and spoon tzatziki over the top.
Serve: Enjoy immediately while fresh.