Slice the chicken breast into thin strips and season evenly with sea salt, black pepper, and dried oregano.
Heat the olive oil in a non-stick skillet over medium-high heat.
Add the chicken strips to the skillet and sauté for 5-7 minutes until golden brown and cooked through.
While the chicken cooks, thinly slice the cucumber and red onion, then toss them in a small bowl with the lemon juice.
Warm the tortilla in a separate dry pan over low heat for 30 seconds until soft and pliable.
Spread the hummus in an even layer across the center of the tortilla.
Layer the baby spinach, cooked chicken strips, cucumber, and red onion over the hummus.
Sprinkle with crumbled feta cheese.
Fold in the sides of the tortilla and roll tightly from the bottom to secure the filling.