Place each salmon fillet on an 18x12-in. piece of heavy-duty foil; fold up edges of foil to create a rim around the fish. Spoon lemon juice mixture over salmon; top with lemon slices. Carefully fold foil around fish, sealing tightly.
Place packets in a 15x10x1-in. pan. Bake until fish just begins to flake easily with a fork, 15-20 minutes. Open foil carefully to allow steam to escape.
Meanwhile, place green beans, water and oil in a large skillet; bring to a boil. Reduce heat; simmer, covered, 5 minutes. Stir in remaining ingredients; cook, uncovered, until beans are crisp-tender, stirring occasionally. Serve with salmon.