1. Preheat oven to 400 degrees Fahrenheit (200 degrees Celsius).
2. Place all ingredients except for water into a doubled 9×13-inch (23×33-centimeter) baking pan. Add water to cover. Double wrap pan well with aluminum foil and place in preheated oven.
3. Bake for one hour, then lower the heat to 250 degrees Fahrenheit (120 degrees Celsius) and cook for an additional four hours. Check every hour and add water as needed.
4. Before Shabbos, add a drop more water to the pan and place it on your blech before Shabbos, or leave in the oven on 200 degrees Fahrenheit (95 degrees Celsius°C) until ready to serve.