Preheat your oven to 400°F (200°C) and line a large rimmed sheet pan with parchment paper for easy cleanup.
Slice the yellow squash into half-moons and trim the woody ends off the asparagus spears.
Cut the chicken breast into even 1-inch bite-sized pieces to ensure they cook at the same rate as the vegetables.
In a small glass jar or bowl, whisk together the extra virgin olive oil, lemon juice, dried oregano, garlic powder, sea salt, and black pepper.
Arrange the chicken pieces, squash, asparagus, and whole cherry tomatoes on the prepared sheet pan.
Drizzle the lemon-herb dressing over the chicken and vegetables, using your hands or tongs to toss until everything is thoroughly and evenly coated.
Spread the ingredients out into a single layer, making sure the chicken pieces are not crowded so they can brown properly.
Roast in the center of the oven for 18 to 22 minutes, or until the chicken is opaque and cooked through and the vegetables are tender-crisp.