The story begins in medias res, with Stephen Chow having ordered and subsequently criticized Turkey's (Karen Mok)Assorted Noodles for its lack of taste, terrible choice of ingredients and feces in the pig's colon, as she lashes out at him for his criticism towards her cooking. He tells her he is the God Of Cookery.
The God of Cookery is the story of celebrity chef Stephen Chow (the Chinese characters used for Chow's name in the movie is different from Chow's actual name), who knows very little about cooking and is willing to hawk any product for a price. The arrogant and cocky Chow is known as the "God of Cookery" and runs a successful business empire, as well as appearing as a judge for culinary competitions rigged to make him look good.
When Bull Tong (Vincent Kuk), posing as an understudy, exposes Chow as a fraud during the opening ceremony of Chow's 50th restaurant, Chow's business empire is taken away. Bull was conspiring with Chow's business partner (Ng Man Tat) to overthrow him. Ruined, Chow lives on the streets in an area known as Temple Street where the story continues with Stephen subsequently being assaulted by thugs. Two rival street vendors, Goosehead (Lee Siu-Kei) and Turkey (Karen Mok), conduct gang warfare to see which vendor can sell the two best-selling dishes: beef balls and"pissing" shrimp. Chow manages to unite the two rival vendors by combining the two dishes into a new dish, "Pissing Beef Balls", which the three of them could sell together. It becomes a huge success, and the vendors convince Chow to enroll in a culinary school in order to reclaim the title he lost, but not before he discovers that Turkey idolized Chow as the "God of Cookery", and received her scarred appearance due to her devotion.
The success of the "Pissing Beef Balls" alarms Bull, the new "God of Cookery", who arranges for Chow to be assassinated on the way to culinary school. Turkey, however, takes the bullet instead, and Chow, presumed dead, disappears.
One month later, Bull enters the "God of Cookery" competition (a parody of Iron Chef) as the heavy favorite to retain the title. Chow arrives at the competition at the last minute, and reveals to Tong what had happened: Chow escaped the assassin's second bullet, and found his way to a Shaolin monastery, where head monk Wet Dream (a spoof on the Chinese word for nocturnal spermatorrhea) nursed him back to health. However, Wet Dream would not allow Chow to leave the temple until he was well-versed in the ways of the Shaolin arts, a point made moot when it is revealed the culinary school he was going to attend was, in fact, the temple's kitchen—the same kitchen Bull had trained at for 10 years, but subsequently dropped out of. While training, Chow continually mourned for Turkey, and was overcome with grief and remorse over his careless treatment of her. The depth of his feeling, which caused his hair to grow white, convinced Wet Dream to allow him his departure from the monastery.
The competition between Chow and Tong begins in earnest, with the two attempting to make identical Buddha Jumping Wall dishes. Each chef tries to sabotage the other's dish in a comedic wuxia fashion by attacking the other using their ingredients and kitchen implements, but Tong prevails when Chow's ex-business partner makes Chow's container explode with a bomb. With few materials and little time remaining, Chow prepares "Sorrowful Rice", a simple dish of barbecue pork on rice with an egg and onions, the same dish Turkey first gave to him while he was living on the streets. Although "Sorrowful Rice" is the better dish, Tong had already blackmailed the judge (Nancy Sit) into rigging the contest. Through divine intervention, Tong is apparently killed and Chow's former business partner is reverted into his true form of a bulldog. It is also revealed in a former life, Chow was an assistant to the Kitchen God in the Imperial courts of Heaven, before being sent to Earth as punishment for revealing culinary secrets to mankind.
After the competition, Chow celebrates Christmas with his vendor friends in Temple Street, where Goosehead reveals that Turkey survived the assassination. She caught the bullet meant for Chow with her gold-plated teeth and a dentist reconstructed her dental work and even threw in a free plastic surgery on her face, making her pretty again.