Preheat your oven to 425°F (220°C).
Rinse the baby potatoes and gently boil them in lightly salted water until just tender, about 10-12 minutes.
While boiling, combine the chicken breast with the juice of half a lemon, minced garlic, mixed chopped herbs, salt, and pepper in a bowl. Let it marinate for at least 10 minutes.
Drain the potatoes and place them on a baking tray. Gently press each potato with the bottom of a glass to slightly smash them. Drizzle with olive oil, and season with a pinch of salt and pepper.
Place the smashed potatoes in the oven and roast for 20-25 minutes or until they become crispy on the edges.
While the potatoes roast, heat a non-stick skillet over medium heat. Cook the marinated chicken breast for about 5-7 minutes per side until fully cooked and lightly charred.
In the last 10 minutes of the potatoes' roasting time, add the green beans to the tray, lightly tossing them in any remaining olive oil and a sprinkle of salt and pepper.
Once everything is cooked, plate the sliced chicken breast alongside the crispy smashed baby potatoes and roasted green beans. Garnish with a final squeeze of lemon if desired and enjoy!