Preheat oven to 450°F. Coat a large baking dish or cast-iron skillet with 1 tablespoon of the olive oil. Arrange the lemon slices in a single layer in the bottom of the dish or skillet.
In a large bowl, combine the remaining oil, lemon juice, garlic, salt, and pepper; add the green beans and toss to coat. Using a slotted spoon or tongs, remove the green beans and arrange them on top of the lemon slices.
Add the potatoes to the same olive-oil mixture and toss to coat. Using a slotted spoon or tongs, arrange the potatoes along the inside edge of the dish or skillet on top of the green beans.
Place the chicken in the same bowl with the olive-oil mixture and coat thoroughly. Place the chicken, skin-side up, in the dish or skillet. Pour any of the remaining olive-oil mixture over the chicken.
Roast for 10 minutes, then reduce the temperature to 400°F and continue to bake for an additional 40 minutes. Remove the chicken from the dish or skillet. Place the beans and potatoes back in oven for 10 minutes more, if needed, until the potatoes are tender. Serve warm.