Bring a large pot of water to a boil. Add the green beans and blanch them for 2 to 3 minutes, until tender but still crisp. Drain the beans in a colander and immediately put them into a bowl of ice water to stop the cooking and preserve their bright green color.
For the gremolata, toss the garlic, lemon zest, parsley, parmesan, and pine nuts in a small bowl and set aside.
When ready to serve, heat the olive oil in a large sauté pan over medium-high heat. Drain the beans and pat them dry. Add the beans to the pan and sauté, turning frequently, for 2 minutes, until coated with olive oil and heated through.
Remove from the heat, add the gremolata and toss well.
Sprinkle with lemon juice and serve.