Preheat your oven to 425°F (220°C).
In a small bowl, whisk together the juice of 1/2 lemon, olive oil, chopped mixed herbs, minced garlic, salt, and pepper.
Place the 5 oz chicken breast in a shallow dish and coat evenly with the lemon-herb marinade. Let it rest for 10 minutes to absorb the flavors.
Peel and cube the medium sweet potato into uniform pieces for even roasting. Toss the cubed sweet potato with a little olive oil, salt, and pepper.
Arrange the seasoned sweet potato cubes on a baking sheet and roast in the preheated oven for about 20 minutes.
While the sweet potatoes are roasting, season the chicken breast with a little more salt and pepper, then heat a skillet over medium-high heat. Sear the chicken for 3-4 minutes on each side until the exterior becomes crispy and golden.
After searing, transfer the chicken to the oven (if space allows, or cover the skillet) to finish cooking for another 8-10 minutes until the internal temperature reaches 165°F (74°C).
Steam or lightly sauté the green beans until they are tender but still crisp, about 4-5 minutes.
Serve the crispy lemon-herb chicken alongside the roasted sweet potatoes and green beans for a balanced, flavorful meal.