As far as I can tell, the Swiss Army is fuelled by Kambly biscuits and Käseschnitten. 

The Swiss Army

All men in Switzerland must do mandatory military service. Normally they do an initial 18 to 21 week basic training, and then every year for at least the next decade they are required to go back to the army for a three or four week refresher. If a man is unfit for service, or a conscientious objector, he is required to do civil service instead. Women can volunteer for military service if they choose, but they represent only about 3% of the troops.

Part of Sam's army service involved choosing the weekly menus at camp and ordering the bulk food needed to feed the battalion. He still has his military cookbook with every recipe calculated to feed a hundred men.

It isn't just the Army cookbook that mentions the military version of the Käseschnitte. It was focus of this 1988 episode of the now entertainingly dated TV show Coop Mittwoch Studio. This weekly program was put on by Coop, one of the two big supermarket chains in Switzerland, and featured products from the shops as well as recipes. It's worth a watch for the outfits and theme song alone. 

The bit on the Militärkäseschnitte is at the 01:25 minute mark and opens with the host saying in Swiss German:

Im Militär muess meischtens alles schnall goh und trotzdäm guet sii.

In the military, things often have to happen quickly, but still be good.

Quick and good definitely describes the Militärkäseschnitte. Although the cheese batter needs a resting time of about three hours, once it's ready the cooking is a snap. It must be excellent fuel for the soldiers, I mean, what's more solid than an eggy cheese mix spread onto thick bread and fried in butter?

Any hard cheese will do. I used some Alpkäse purchased at the Entlebucher Alpabzug.

120 g hard cheese, grated

50 g flour

1 egg

100 mL milk

pinch of nutmeg, salt and pepper

knob of butter

approx 3 thick slices of bread

In a medium bowl, mix together the cheese, flour, egg, milk and seasonings. Cover and let rest in the fridge for at least three hours.

After three hours, give the cheese mixture a good stir and spread half on the bread slices, pressing it down a bit to make sure it sticks to the bread.

Heat butter in a large frying pan on medium heat until it bubbles and splutters.

Place the slices of bread CHEESE SIDE DOWN into the frying pan. Try not to move them around in the pan too much, just let them crisp up. As the cheese melts, it will adhere better to the bread.

While the slices are frying face down, spread the remaining cheese mixture on their exposed side.

After a few minutes, once you can smell the cheese, take a peek underneath and if it is golden brown, carefully flip the bread. 

Fry the second side for a few minutes, until golden brown. 

• Gruyère, Alpkäse, Cheddar or any other hard cheese will work.

• You need quite a bit of fat in your frying pan to make sure the cheese doesn't stick. If it is looking dry when it comes time to flip, add a little more.

• If you aren't so keen on frying, these can be baked at 200 C / 400 F / gas mark 6 for about 15-20 minutes. Alternatively, stick them under the broiler until they turn golden brown, or use a toaster oven.

• Serve with cooked apples or applesauce and a green salad.

• For a quicker, baked version with no resting time, see here.

(not an army sanctioned knife...)