Season the chicken breast with half of the sea salt and black pepper.
Heat a skillet over medium-high heat with a small drizzle of olive oil and sear the chicken for 5-6 minutes per side until fully cooked and golden.
While the chicken rests, chop the cucumber into half-moons, halve the cherry tomatoes, and thinly slice the red onion.
In a small glass jar or bowl, whisk together the extra virgin olive oil, fresh lemon juice, chopped parsley, dill, and the remaining salt and pepper.
Slice the rested chicken breast into thin bite-sized strips.
In a large serving bowl, combine the mixed baby greens with the prepared vegetables and sliced avocado.
Add the chicken to the bowl, drizzle with the lemon-herb vinaigrette, and toss gently to coat before serving.