PrepSheet

Jacket potato with tuna mayo: how much it costs to make, per serve

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A large baked potato (about 375 g) split and buttered, filled with tuna mayonnaise with sweetcorn and served with a small salad of iceberg and cucumber. Costed from JJ Foodservice wholesale prices dated 9 October 2026.

Ingredients per serve£1.31
Sell at 25% food cost£6.27 inc VAT (£5.23 ex)

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Ingredients and cost, one serve

IngredientPack pricePack sizeUsedCost
Baking potatoes (about 40 to a case)£12.9940 each1 each£0.32
Unsalted butter£30.495000 g10 g£0.06
Tuna chunks in brine (130 g can weight, about 95 g drained)£7.491700 g130 g£0.57
Mayonnaise£15.495000 ml35 ml£0.11
Sweetcorn£5.992230 g30 g£0.08
Iceberg lettuce£9.9910 each0.1 each£0.10
Cucumbers£7.9914 each0.1 each£0.06
Table salt£10.996000 g1 g£0.00
Total£1.31

Cost per line is pack price × (amount used ÷ pack size), the same sum the tool runs. Change one pack price and every line that uses it moves.

Method

  1. Rub the potato with a little salt and bake at 200 °C for 60-75 minutes, until the skin is crisp and a knife goes in with no resistance.
  2. Drain the tuna well, then mix with the mayonnaise and sweetcorn; season.
  3. Split the potato, butter it, pile in the filling and add the side salad.

Costing notes

The tuna is costed on can weight because that is what you pay for: a 1.7 kg catering tin drains to roughly 1.2 kg of fish, so 130 g from the can gives about 95 g of tuna on the potato. Pre-made tuna mayo filling (about £8.49 for 1 kg at JJ the same day) costs more per portion but saves prep time.

A case of about 40 baking potatoes means potatoes of roughly 375 g; if your case comes in at 50, each potato is smaller and cheaper, and the portion looks it.

Where the prices came from

JJ Foodservice collection prices as shown on its public search pages on 9 October 2026 (delivery runs about £1-2 a case higher). A few lines JJ did not list in that day's searches reuse the dated prices already on our other starter recipes (7 September 2026, JJ Foodservice or Tesco retail, marked on each line). JJ does not label VAT on most lines: raw food is zero-rated in the UK, while soft drinks, alcohol, confectionery and some ingredients carry standard-rate VAT. Your supplier's price is the one that matters: open the recipe and type it in.

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