About 30 minutes.

It is best to use rice and cook it until it becomes sticky, about 30 minutes. Soak the pot with salt water first, then cook the porridge, first on low heat, and then gradually increase the heat. After the porridge is boiled, lower the heat and let it sit for a while.

Extended information

1. Warm it gradually and do not burn it suddenly on the fire to avoid swelling and cracking.

2． After the food is cooked, when the casserole is removed from the fire, use wood chips to support the pot to dissipate heat evenly and cool it slowly to avoid shrinkage and cracking. You can also make an iron ring according to the size of the casserole. After the casserole is removed from the fire, place it on the iron ring so that the bottom does not directly touch the ground and is suspended in the air to cool down naturally, which can make the casserole last longer.

3. Do not use casseroles for cooking. Generally, casseroles are used for soups and vegetables. Because the oil for cooking is very hot, when the oil in the pot is heated, if cold vegetables are suddenly put in, the pot will easily explode. Therefore, when cooking, you should add water first before moving it to the fire. If you boil the pot first and then put the water in, it will easily cause the pot to burst. When using a casserole to make soup or stew meat, you should first put water into the casserole, then put the casserole on the fire, first use a slow fire, and then use a high fire.

4. When removing the casserole from the fire, place it on a dry wooden board or straw mat, never on a tile or cement floor.

5. Do not use a casserole to cook sticky food.

6. Don’t dry-burn, and don’t wash with water when it’s still hot, as this may cause cracks.

7. Do not wet the bottom of the pot. When washing the pot, try not to get the bottom of the pot wet, and make sure the bottom of the pot is dry when cooking. Before each use, wipe away the water from the outside of the casserole.

Reference: Baidu Encyclopedia-Casserole