In my conception, any activity can be an Art as long as it is equipped with a potential for creativity. In this sense, clearly, Cooking, at least in a certain form (unfortunately not the one I am able to practice), is an Art. Cooking is indeed an activity that requires a certain level of skills and knowledge and which, beyond a certain level, does provide its practitioner with the possibility of inventing and being creative.
Even historically, Cooking presents some characteristics of an established art. We owe to Escoffier and to his Guide culinaire published at the beginning of the 20th century, the first theorizing of this Art. It would be restrictive however to limit Cooking to Escoffier's point of view (even though, in practice today, it is almost the unique point of view), the fact is that there has been in history other approaches to Cooking, the Chinese approach for instance is quite interesting to consider.
In musical and poetical treatises, Chinese authors often referred to the art of cooking to draw analogies about flavor:
"Hence the greatest achievements of music were not in the perfection of the airs; the (efficacy) of the ceremonies in the sacrificial offerings was not in the exquisiteness of the flavors. In the lute's for the Qing Miao the strings were of red (boiled) silk, and the holes were wide apart; one lute began, and (only) three others joined it; there was much melody not brought out. In the ceremonies of the great sacrifices, the dark-colored liquor took precedence, and on the stands were uncooked fish, while the grand soup had no condiments: there was much flavor left undeveloped. Thus we see that the ancient kings, in their institution of ceremonies and music, did not seek how fully they could satisfy the desires of the appetite and of the ears and eyes; but they intended to teach the people to regulate their likings and dislikings, and to bring them back to the normal course of humanity."
[LiJi 禮記 (Book of Rites),"YueJi" 樂記 (Classic of music), 6]
Or, about poetry:
"If we want to enjoy the poetry of Tao YuanMing, Wang Wei, Wei YingWu or Liu ZhongYuan, we must look for the true flavour within which is bland and flat. At first, we don't notice it, but it becomes unforgettable as we go on tasting it. Thus it is that, when Lu HongJian tasted the flavor of various spring waters, across the world, he gave the first rank to the water of the Great River at ZhongLing. The flavour of water is bland, but in fact, it is not bland: it is the best flavor of the world, and the flavor of no other food compares to it. Indeed, "those who can enjoy the flavor of food" are already "rare", but those who know how to enjoy the flavor of water are even rarer."
[Wang ShiZhen 王士禎, 17th century, in Qing ShiHua 清詩話(Shanghai: Shanghai guji. chubanshe, 1999)]
As it is, therefore, far from regretting the insipidity as Escoffier does in his Guide Culinaire (talking about the abusive use of the spanish sauce):
"To its abuse, we can impute the development of this neutral cuisine, without well-defined aroma, where all the notes of the flavoric scale were confused in only one insipid tone"
[Le Guide Culinaire/Grandes Sauces de base/Principes Generaux]
Chinese chefs could use a bit more of this spanish sauce, in order to reach the ideal of Chinese Cuisine: PingDan 平淡 (insipid). That is, if chinese cuisine was still aspiring to such an ideal (but did it ever?), which does not seem to be the case, given the popularity of MSG in Chinese restaurants, MSG being a flavor enhancer, naturally contained in Soy Sauce or Fish Sauce.
And this evolution allows me to come to what really occupies my mind with the concept of Cooking as an Art. An art at some level ought to provide its "audience", with some kind of enlightenment, or at least it does in my understanding of what an art is. For that, it needs to have some philosophical basis, of the kind we may find in the traditional chinese conception: as said above in the Book of Rites, it is intended to teach something(beyond words) to the people, to bring them back towards a conception of humanity, to restore a balance. That dimension, in my view, is largely lacking in the contemporary world of Cuisine, even though there are some notable exceptions. Generally therefore, I feel Cuisine is, more often than not, and even in some reputable restaurants, reduced to providing some sophisticated version of comfort food.
But if Cuisine is really to elevate itself to the level of Art, its "audience" should first accept to be challenged by what they are served with.
Clearly though, not each and every meal is to be an artistic experience, and comfort food will always exist, just like comfort music and comfort literature, and will always represent the most common kind of food for any person, but Cooking can also be an Art, under the condition of providing its "audience" with a challenge that will take it away from the habit of immediate enjoyment towards a more reflective, a more properly human form of enjoyment (in opposition to the bestiality of direct satisfaction). Nothing more than Cuisine can achieve that goal with more success because taste is a more intense sense than audition or vision which are the usual domain of Art.