“If you want to know what’s good and what’s bad in any town, you ask a cabdriver,” said Hesham Hegazy, the director for business and brand development at Halal Guys. “It took no time for the word to get out and the line to start building.”

Image From left, Abdelbaset Elsayed and Mohamed Abouelenein, the food cart’s founders, with Hesham Hegazy, a manager. Mr. Abouelenein’s three children have attended LaGuardia. Credit... Dave Sanders for The New York Times

The Halal Guys first donated to LaGuardia, which is in the Long Island City neighborhood, in 2013, when their entire operation was a couple of food trucks, some piles of meat and pita bread serving the lunch crowd. Today, they have signed about 335 franchise agreements, Mr. Hegazy said, with locations in the Philippines, California and Texas. This gift, like the two previous ones, will go to the Halal Guys scholarship fund, which is somewhat less famous than their gyros or the white sauce on them.

The gift is being funded by Dan Rowe, the chief executive of Fransmart, the restaurant franchise consulting firm that works with the Halal Guys. He had promised Mr. Hegazy that if the company signed a deal in South Korea, he would give part of his commission to LaGuardia, which serves 50,000 students a year, most of them poor and many of them immigrants. Mr. Abouelenein, one of the founders, sent three of his children there, one of whom now runs the company.

At lunchtime on Thomson Avenue on Wednesday, two or three food carts dotted each block on the busy thoroughfare. There was a Korean Grill and a coffee cart (“If you’re not shaking, you need another cup,” a sign near the bagels read). There was a waffles-and-crepes truck, and a cart offering cheeseburgers and lamb gyros. There was a lonely-looking woman selling fruit.