Preheat your oven to 400°F (200°C) and line a large rimmed sheet pan with parchment paper for easy cleanup.
Dice the yellow potatoes into half-inch cubes and snap the woody ends off the asparagus spears.
In a small glass bowl, whisk together the olive oil, lemon juice, minced garlic, dried oregano, sea salt, and black pepper.
Place the chicken breast, cubed potatoes, asparagus, and cherry tomatoes onto the prepared sheet pan.
Drizzle the lemon-herb marinade over the chicken and vegetables, tossing everything thoroughly to ensure an even coating.
Spread the ingredients out into a single layer, making sure the chicken pieces have enough space to roast evenly.
Slide the pan into the oven and bake for 20-25 minutes, or until the chicken reaches an internal temperature of 165°F and the potatoes are golden and fork-tender.
Remove from the oven and allow the chicken to rest for 5 minutes before slicing to keep it juicy and flavorful.