Your supplier has just put 18p on the cost of your burger. Absorb it, and it costs you £3,240 a year.

"Let's give away £4,212 this year." Nobody stands at the pass and decides this, and yet it happens every day. Not through theft, not through waste, tot because anybody is trying to do a bad job. It happens because a scoop is a little too full. The chef plates what looks right rather than what the specification says. Thirty grams here, twenty grams there. Service after service. Day after day.

"Let's spend an extra £7,000 a year on food purchases" Nobody ever sits in a management meeting and says that. And yet it happens all the time, not because somebody makes a reckless decision, approves a higher budget or deliberately chooses higher costs. It happens because convenience slowly becomes the purchasing strategy.

A chef sent over his dish costs and GP calculations for a menu engineering report I was putting together. One steak dish was showing a GP of 75.7%. That immediately raised an eyebrow. For the selling price involved, the margin looked unusually strong. When I checked how he'd worked it out, I found the problem straight away: he'd left VAT in the selling price. Removing the VAT element brought the revenue down from £24.00 to £20.00 ex-VAT and the GP down to 70.9%.