Preheat your oven to 400°F and line a large rimmed baking sheet with parchment paper.
Peel the carrots and slice them into 1/2-inch thick rounds on a diagonal for more surface area.
Cut the chicken breast into uniform 1-inch cubes to ensure even cooking.
In a large mixing bowl, combine the carrots, chicken, olive oil, minced garlic, sea salt, and black pepper.
Toss everything thoroughly until the chicken and carrots are evenly coated in the oil and seasonings.
Spread the mixture in a single layer on the prepared baking sheet, ensuring pieces aren't overcrowded.
Roast for 20 to 25 minutes, or until the chicken reaches an internal temperature of 165°F and the carrots are fork-tender.
Remove from the oven and immediately toss with the chopped fresh dill and lemon juice while still hot.
Serve warm, ensuring each portion gets a generous amount of the herb-infused pan juices.