Deep-frying cooks food in hot oil.

It makes the outside crispy.

Cookbook author Betty Liu uses this method in the "Frying" chapter of her book "The Chinese Way."

She wants the oil at 350°F to 375°F.

She uses a thermometer.

A wooden chopstick can also test the heat.

Tiny bubbles rising fast mean the oil is ready.

Deep-frying often uses a double-fry technique.

People in Shanghai have used it for a long time for shrimp and fish steaks.

Liu says it works very well for chicken.

The first fry is at a low temperature.

It keeps the juices in and sets a light coating.

The second fry is at a higher temperature.

It cooks the chicken all the way through and makes it crispier.

Her coating uses cumin for flavor and crushed sesame seeds for texture.

The chicken sits in the marinade for at least 4 hours or overnight.

Then she covers it in a mix of sesame seeds, sugar, potato starch and cumin.

The first fry is at 335°F for about 90 seconds.

The second fry is at 350°F for 3 to 5 minutes.

It is done when the chicken reaches 165°F inside.

Liu serves the chicken with a cumin salt and a lemon mayonnaise if you want.

She is a cookbook author, photographer and doctor.

She is finishing her surgical residency.

She writes about Chinese home cooking on her award-winning blog.

Her first book, "My Shanghai," came out in 2021.

It was named one of the year's best cookbooks.