In a small bowl, whisk together the olive oil, lemon juice, dried oregano, sea salt, and black pepper to create a marinade.
Place the chicken breast in a shallow dish and coat thoroughly with the marinade, letting it sit for at least 10 minutes.
Preheat a grill pan or outdoor grill over medium-high heat and cook the chicken for 5-7 minutes per side until the internal temperature reaches 165°F.
While the chicken is grilling, slice the cucumber into rounds and halve the cherry tomatoes.
Remove the chicken from the heat and let it rest for 3 minutes before slicing into thin strips.
Spread the hummus onto one side of a large plate or shallow bowl.
Arrange the sliced chicken, cucumbers, tomatoes, and kalamata olives on the platter.
Garnish the entire dish with crumbled feta cheese and an extra squeeze of fresh lemon if desired.