Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper.
Slice the zucchini into half-moons and place them on the baking sheet along with the cherry tomatoes.
Drizzle the vegetables with olive oil, sprinkle with half of the sea salt and black pepper, and toss until evenly coated.
Roast the vegetables in the oven for 15-18 minutes until the zucchini is tender and the tomatoes have just begun to blister.
While the vegetables are roasting, season the chicken breast on both sides with the remaining sea salt and black pepper.
Heat a non-stick skillet over medium-high heat and sear the chicken for 6-7 minutes per side, or until the internal temperature reaches 165°F.
Remove the skillet from the heat, drizzle the chicken with lemon juice, and spread the basil pesto evenly over the top of the breast.
Plate the pesto-topped chicken alongside the roasted zucchini and tomatoes, drizzling any remaining pan juices over the vegetables.