1. Marinate the Chicken: In a bowl, combine olive oil, lemon juice, garlic, and oregano. Add chicken breasts and marinate for at least 30 minutes.
2. Preheat Grill/Oven: Set your grill to medium-high heat (375°F) or preheat your oven to broil.
3. Cook the Chicken: Grill chicken for about 6-7 minutes per side or broil in the oven for about 10-15 minutes until fully cooked.
4. Prepare Your Veggies: While chicken cooks, dice cucumber and halve cherry tomatoes; season with salt and pepper.
5. Slice and Assemble: Let the chicken rest before slicing into strips. Layer sliced chicken over veggies in bowls or a serving dish.
6. Top It Off: Sprinkle with feta cheese and drizzle with leftover marinade.