VATICAN CITY (AP) ― If an army travels on its stomach, what does the world’s smallest army eat?

A chef who serves in the Swiss Guards, David Geisser, is shedding light on the culinary tastes of the pope’s army with a new cookbook. “Buon Appetito” featuring recipes on the soldiers’ current menu and some dishes inspired by the tastes of popes past and present.

A favorite meal for the 110-strong Swiss Guards is eggplant parmesan: pieces of breaded, fried eggplant that are topped with tomato sauce and mozzarella and baked for 15 minutes.

“This recipe we eat a lot of times here,” Geisser, 24, said in an interview inside the kitchen of the Swiss Guard canteen, where Polish nuns do most of the cooking.

A glance at the weekly menu hanging in the barracks’ kitchen reveals an abundance of Italian dishes such as risotto, four-cheese pasta and tortellini alongside northern European stalwarts like sausage and sauerkraut.

The papal menus in the book cater to the regional tastes of the last three popes.

The Pope Francis menu features Argentine specialties: empanadas (folded pastries filled with meat, cheese or vegetables), beef and dulce de leche (a caramel dessert topping made from condensed milk).

The menu for Bavarian-born Benedict XVI includes sausages and roast pork, while the John Paul II menu has pierogi (stuffed Polish dumplings) and an apple tart.

Geisser, who is nearing the end of his two-year service, has never cooked for Francis but gave him a copy of the cookbook.

“He saw the photos and the book and he was really happy,” Geisser said.

First released in German in October 2014, Geisser said the cookbook is being rolled out in English, Spanish, French, Italian, Russian, Korean, Polish, Korean and Slovak versions.

The Swiss Guards, distinguished by their Renaissance-style blue and gold uniforms, plumed helmets and halberds, carry out ceremonial duties, assist at Vatican functions and protect the pope.