Place the green beans in a medium saucepan and mix in the garlic, water and lemon juice. Cover and bring to a boil. Cook, stirring occasionally, 8 to 10 minutes, until tender but crisp. Drain and transfer to a medium bowl.
In a small bowl mash the anchovy fillets and about 1 tablespoon reserved oil. Toss into the bowl with the green beans. Season with pepper. Serve immediately.