Watch how it’s made
Every step in 1:06 — from the ingredients to the finished dish.
This is the lowest-carbohydrate item on the site at 6 grams, and it takes ten minutes with a tin from the cupboard. It is the snack for the afternoon when you are genuinely hungry rather than bored, and when whatever you eat next needs to not move your glucose much.
Twenty-two grams of protein in a snack is unusual. Most things eaten between meals carry almost none, which is the reason they stop working an hour later.
Water-packed, not oil-packed
The distinction matters more than it sounds. Tuna in water drains to almost pure protein. Tuna in oil retains a good deal of that oil even after draining, and the oil used is usually soybean or sunflower rather than olive.
If you buy oil-packed, buy the kind packed in olive oil and count it. If you buy water-packed, drain it hard by pressing the lid down over the tin.
A word about mercury
This is worth being straight about. Light skipjack tuna is low in mercury and the FDA lists it among the fish safe to eat two to three times a week. Albacore, sold as white tuna, carries roughly three times as much and the guidance is once a week.
For a snack you might make often, light tuna is the sensible default. If you are pregnant, the advice is stricter and worth checking with your own care team.
Yogurt instead of mayonnaise
Two tablespoons of mayonnaise carry about 20 grams of fat and no protein. The same amount of Greek yogurt carries under a gram of fat and 3 grams of protein.
Yogurt alone tastes lean and slightly sour, so a teaspoon of Dijon and a squeeze of lemon do the work the mayonnaise was doing. A single teaspoon of mayonnaise stirred in alongside the yogurt is a reasonable middle if you miss it.
Making the boats
Halve the cucumbers lengthways and run a teaspoon down the middle to scoop out the seeds. That channel is what holds the filling, and the seeds are the wettest part of a cucumber.
Leave the skin on. It is where most of the cucumber fiber sits, and it stops the boat collapsing.
What the celery is for
Texture, mostly. Tuna and yogurt together are soft, and without something crunchy the whole thing is one note.
Dice it fine. Large pieces of raw celery are stringy and dominate; finely diced it disappears and just registers as crunch.