Presumably the staffing cost is the front of house staff as well as the actual cooking and then the cost of employing someone to wash dishes, clean the restraunt and so on. Then compared to growing asparagus which seems to largely come from countries with substantially lower wages. Restraunts have always been infamously low margin businesses though.

They talk about price per kg but I see 4 on the plate? 12 to 20 gram each. 48 to 80 grams total. 21 to 12.5 portions in a kg. £15 to £20 per 1000g

   15/21   = 0.714
   15/12.5 = 1.20
   20/21   = 0.95
   20/12.5 = 1.60

Then you cant even say it costs 1.60 in ingredients per plate. It might even be that it costs 72 cents and that the customer gets only 60 cents worth of vegetables.

> asparagus can actually be more expensive than some proteins

It's not actually the asparagus but the preparation that costs money.

> Overall, the ingredients for this dish are around £3, but the labour, energy and everything else comes to £56

Say 60 which is 100 times 60 cents or 3-4 kg.

The hidden cost is real estate for both the restaurant and the employees. They have few seats and the usual menu has a lot of different things.

If say the city would buy the surrounding buildings (which is a good investment) and provided say 2000 to 7000 seats for free (we've already paid taxes) then reduce the menu to 3-4 meals that you pick up yourself at the counter people could eat there for next to nothing (which would be good for the economy)

It wouldn't be the same experience of course.