Wash 1-1/2 cups Lima beans and cook gently in plenty of water, with salt to taste. Drain and add sufficient water to make 3 cups liquid. Add 3 cups sliced raw potatoes and salt to taste, and let boil gently until the potatoes are tender. Stir 1 tablespoon vegetable butter with 1 tablespoon flour in a saucepan over the fire until blended, add a little of the broth and stir smooth. Add more broth, and pour over the cooked potatoes. Add the cooked beans, shake together, and pour into an oiled baking pan. Cover with pie crust, and bake to a light brown.