Springfield, Mo.

STANDING in the parking lot of Mr. Yen’s, a 560-seat palace of Chinese cooking owned by a family friend, David Leong scanned the red clay pagoda roof and rose-colored walls and staked a claim that few here in the Ozarks would dispute.

“All this came from my cashew chicken,” said Mr. Leong, the 88-year-old patriarch of the Chinese food industry here. “All these restaurants. This wealth. From my family.”

Cashew chicken, in the form first cooked by Mr. Leong nearly a half-century ago, is not the stir-fry served by many Chinese-American restaurants. Around Springfield, cashew chicken  deep-fried chicken chunks in a brown slurry of soy sauce, oyster sauce and stock, scattered with green onions and halved cashews  is the culinary common denominator. It’s a weeknight dinner, bought from a drive-through. It’s a weekday plate lunch, accompanied by fried rice and an egg roll.

More than 70 Chinese restaurants in this city of 157,000 serve cashew chicken, from Lucy’s Chinese Food, a three-location chain owned by brothers John and Tom Gregoroski, to the Canton Inn, a converted Dunkin’ Donuts where Chiwa and Foon Wong keep a pot of chicken stock simmering on the stove and the cashew chicken special costs $3.75.