Preheat the oven at 350°F. Mix all ingredients in a large bowl, except the water. To flavour the biscuits, add a flavoring ingredient to the water. I often use chicken stock or beef stock, my dog loves it. The batter is pretty heavy, it's normal! Roll the batter about ¾ of an inch thick on a flat surface, using a bit of flour under so it does not stick. Cut the batter using dog biscuit cookie cutters or a knife. Place the cookies on a baking sheet. Cook for 20 minutes, then turn the cookies over and cook for another 20 minutes. Then, turn the oven off and let the cookies dry out for an hour or two.