Halal cooking refers to rules outlined in the Muslim religion that dictate what can be eaten. These rules determine what can and cannot be prepared and how permitted foods should and should not be prepared. Additionally, any foods that are unfairly obtained, that come into contact with non-halal foods, or that are associated with idolatry are not appropriate for Muslims.
The Quran, the Muslim holy book, orders followers to eat lawfully. This is taken to mean that Muslims should avoid foods that are haram, or forbidden, and consume only those that are halal, or permitted. The pig, for example, is an animal whose consumption is expressly forbidden. Therefore, halal cooking prohibits the use of any parts of the pig or products that may be made from it.
Many other items are forbidden by way of description of their characteristics as opposed to being specifically named. These include both birds and beasts of prey. Vermin, poisonous creatures, and carrion-eating birds are forbidden. Intoxicating ingredients are also considered haram, so halal cooking should omit the use of items such as a wine or beer.
Animal fats are considered haram. Halal cooking, therefore, requires the use of vegetable oils. When using cheese, it should be vegetarian, which indicates that rennet was not used. Gelatins should also be avoided unless they are also deemed vegetarian. Also, if food has been blessed in the name of any deity or entity other than Allah, it cannot be used for halal cooking. Muslims have extremely strict beliefs about eating any foods associated with idolatry.
After considering the types of meat that may and may not be eaten, a person must consider how an animal died before preparing its meat. Halal cooking prohibits the eating of animals that died of their own accord, such as one that becomes entangled and strangles to death, or animals that were killed by blunt trauma, such as those being stoned to death. Furthermore, once an animal has been slaughtered, it can be cooked only if the blood is allowed to drain from it. There is a halal certification scheme that makes it easier for consumers to identify which items are permissible, though these may not be widely available in all areas. As Muslims are prohibited from consuming blood, rare red meat would violate the rules of halal cooking.
The fact that an item is generally permissible and is prepared appropriately still does not guarantee that it is lawful for Muslims to eat it. Halal cooking also takes into consideration how food is obtained. If a person acquires food through dishonest means, such as cheating someone, that food becomes haram. The same applies if an otherwise halal food comes into contact with a haram food, either directly or indirectly, such as when cooking utensils are shared.