Place 4 12x12 pieces of aluminum foil on the counter. Begin to layer and divide the kielbasa, potatoes, onion, bell pepper, green beans, and garlic in the center of the aluminum foil. Then place 1 tablespoon of salted butter in each foil pack. Season each foil packet with Cajun seasoning and salt (optional). Drizzle on the olive oil one by one and begin to close the packets. Fold in half and then gather each side up toward the sky, crinkle and close until sealed tight. You do not want any air (steam once cooking) or juice to escape.