Galaktoboureko

Scoring 28 recipes

• Lift one cut open with a fingertip: it parts through the skin and stops in the fat beneath, showing a pale wall at its base. Any cut showing red or fibrous flesh has gone too deep; any that has not reached the fat has left the skin tethered, and it will tighten under heat.
• The lines run parallel at even spacing, roughly a finger's width apart, each carried the full length of the face and stopped the same margin short of the edge. Sight down them: lines that converge, wander or crowd at one end cook at different rates and read as careless on the plate.
• Each line is one clean draw of the blade held at a slant, not a sawn or doubled track, and it leaves a bevelled lip standing slightly proud rather than a vertical slot. The surface should be dry and cold, near 4C (39F), when it is cut; worked warm and slack it drags, and the blade tears where it should part.
• After cooking the cuts have opened and set, each a clear gap with firm browned walls. Lines closed back to faint scratches were cut too shallow or too straight down, and the surface has shrunk over them instead of through them.
• The piece lies flat and true when it is set down, with no cupping through the middle and no lifted, curled edge. A bowed piece means the tightening surface was never released, so it pulled the whole thing up and left the underside pale where it stood off the heat.

Where it goes wrong The blade was pushed rather than drawn, through a surface left warm and slack, so it went past the fat and into the flesh. The cuts bleed as they cook and the juices flood the surface, so it steams instead of crisping: the lines gape into wet ragged trenches, the flesh between them dries into hard ridges, and the skin stays leathery and pale where it should have blistered and set.

Tempering a custard 59 recipes

• The hot liquid went into the eggs a little at a time with constant whisking, and only then did everything go back to the pot.
• The heat under it stayed gentle throughout and it was never allowed to boil.
• Stirred continuously and right into the corners of the pan, where it thickens first and sets unnoticed.
• Judged by behaviour: it thickens enough to coat the back of a spoon and hold a clean line when a finger is drawn through it.
• Taken off before it looks finished, and strained. Residual heat carries it the rest of the way, and a custard held on the heat until it looks right arrives past right.

Where it goes wrong The hot liquid went in too fast, or the pot went back over full heat to save time. The yolks set into threads before they could thicken smoothly, and a scrambled custard does not come back; straining hides a little of it and nothing hides the rest.