Turn oven to warm, or heat to 180 degrees.
Add the green beans, olive oil, salt, and pepper to a large bowl and toss well to combine.
Heat a cast iron skillet over medium-high heat until very hot.
Add about ¼ of the green beans to the skillet, trying to keep the beans to a single layer, and cook for 2 minutes without stirring.
Stir the beans and cook for 4-5 more minutes or until charred and tender.
Transfer to a rimmed baking dish and place in the warm oven.
Repeat with the remaining green beans.
Transfer all of the beans to a serving dish and sprinkle with the fresh lemon juice. Season with additional salt and pepper, as needed, before serving.
