Sister quick-service chains Checkers & Rally’s also start with frozen fries. To serve them quickly, the chain cooks them about 10 minutes before they’re likely to be needed, but then refreshes them with a quick 10-second dunk in hot oil before serving them.

Mooyah Burgers, Fries & Shakes, based in Plano, Texas, makes its fries in-house from whole No. 1 Russet potatoes — Burbanks for the nine months that they’re available and Norkotahs when they’re not. The potatoes’ glucose content is measured using the same test strips that diabetics use to test their blood sugar, according to vice president of operations Mike Sebazco.

If the glucose content is too high, they’re rested at room temperature to let some of the sugar convert back to starch.

Once they’re at a good starch level, the potatoes are punched into 3/8-inch sticks, with proprietary specs for how to wash them both before and after punching them.

The precise process doesn’t just result in great fries, but it also keeps the cooks engaged.

DMK Burger Bar has won the award for “best fries in Chicago” by Chicago Magazine, and chef and owner Michael Kornick said that one trick is to par-cook the fries in the same oil that they’re finished in.

“When the oil’s brand new and fresh, it’s almost sterile,” he said. The par-cooking doesn’t just make for crispier fries, but it makes the oil — which is mostly vegetable oil with a little beef tallow added — tastier.

Damian Sansonetti learned to make French fries under the watchful eye of Daniel Boulud — he cooked at two of the famous chef’s New York restaurants, db Bistro Moderne and Bar Boulud.

After soaking the cut potatoes overnight and then rinsing them in multiple changes of water for between 30 minutes and 45 minutes, he cooks them in oil at 300° Fahrenheit until they’re firm and form a slight crust, but before they take on any color — around 3 to 6 minutes depending on the potato.

Next Sansonetti spreads the fries out in a single layer and cools them. At service, they’re brought back close to room temperature and fried at 350° Fahrenheit for 3 to 4 minutes. Then they’re salted and served.