Cheapest, fanciest and french-est sandwich there is: The jambon beurre

It was 11pm and I'd just landed from a work trip. The kind where you spend three days in a conference room, eat whatever gets put in front of you, and fly home feeling slightly greasy and socially exhausted. I had two options: spend 18 euros on the airport sausage that would take 25 minutes to arrive, or find a supermarket on the way home.

I found a supermarket. I bought a ficelle, a packet of ham, and a block of butter. Total: 4.20 euros. I made this sandwich standing at my kitchen counter at midnight and it was one of the best things I ate that entire trip.

The jambon-beurre is a French ham and butter sandwich. That's it. No spreads, no cheese, no lettuce. It sounds like a lazy placeholder for a real meal and it absolutely isn't. It's on every boulangerie menu in Paris for a reason.

Ingredients (serves 1)

• 1 ficelle or thin baguette (or a short section of a regular baguette, roughly 25cm)
• 60-80g good quality ham, thinly sliced (moist, not dry-packed)
• 2-3 tbsp room temperature butter (not cold, not melted)
• Optional: a couple of cornichons, or a very thin scrape of Dijon mustard

The butter being at room temperature is not a suggestion. Cold butter tears the bread. Too soft and it disappears into the crumb. You want it spreadable but still holding its shape.

How to make it

Slice the baguette lengthwise down the middle. Don't cut it completely in half. You want it hinged, like a book, not two separate pieces.

Spread butter on both cut sides. Be generous. This is not diet food and it's not meant to be. The butter is what makes it.

Lay the ham across the bottom half. If the slices are large, fold them over each other rather than layering them flat. You want a bit of height, not a thin sheet of ham you won't taste.

Close the sandwich. Press it lightly. Eat it.

If you're using cornichons, slice them lengthwise and tuck them in with the ham. If you're using mustard, spread a very thin layer on one side only and don't tell anyone it's there. Both are good. Neither is required.

On the bread and the butter

The bread matters more than the ham. A ficelle (the thin baguette) is the traditional choice because the ratio of crust to crumb is higher than a regular baguette, which means more texture and less doughiness. If you can't find a ficelle, a regular baguette section works fine. What doesn't work: sliced sandwich bread. The structure is wrong. You need something with a proper crust.

The ham should be moist. The kind sold in paper-thin slices at a deli counter is ideal. Pre-packed supermarket ham works but check the label and avoid anything that lists water as one of the first ingredients. It goes watery in the sandwich.

If you're ever in doubt about whether you've used enough butter, you haven't. Add more.