Pat the chicken breast dry and cut into one-inch bite-sized pieces.
In a medium bowl, whisk together one tablespoon of olive oil, the lemon juice, Dijon mustard, and garlic powder.
Add the chicken pieces to the bowl and toss until they are evenly coated in the tangy marinade.
In a separate bowl, toss the broccoli florets with the remaining half tablespoon of olive oil and the sea salt.
Arrange the marinated chicken and the seasoned broccoli in a single layer in the air fryer basket.
Air fry at 400°F for 10 to 12 minutes, shaking the basket halfway through, until the chicken is golden and the broccoli is crisp.
While the chicken and broccoli cook, dice the cucumber and combine it in a small bowl with the rinsed black beans, apple cider vinegar, and black pepper.
Serve the hot air-fried chicken and roasted broccoli alongside the refreshing, bright cucumber and bean salad.