In a large bowl, combine water, broth, and miso, until all miso is thoroughly broken up. Pour into a Gallon freezer bag. Add the sliced bok choy, cooked chicken, garlic, mushrooms, and oil. Seal bag, removing as much air as possible. Freeze Flat. Gently place cubed tofu into a quart sized freezer bag. Seal, removing as much air as possible without squishing the tofu pieces. Freeze next to the soup bag.