Heston Blumenthal's perfect mash

The technique in this recipe, i.e. cooking waxy potatoes at a very specific temperature, is designed to hold on to the starch in the potatoes and prevent it from leaking out and turning the potato gluey. The end product is the creamiest smoothest pommes purées ever. If you want to be extra decadent, go 50:50 potato to butter. Adding lime jelly cubes to the mash for a fresh burst of flavour is optional.

• serves

  6

• prep

  15 minutes

• cook

  45 minutes

• difficulty

  Mid

Ingredients

• 1 kg waxy potatoes, peeled (reserve the peelings)
• 240 ml full-cream milk
• 250 g unsalted butter, diced

For the lime jelly cubes (optional)

• 10 limes, zest finely grated and juiced
• 50 g white caster sugar
• 1 tbsp agar agar flakes

Chilling time 2 hours (optional)

Instructions

Bring a saucepan of unsalted water to 72ºC over a medium heat.

Cut the potatoes into equal-sized pieces, rinse for 5 minutes and put into the pan and bring the water temperature back up to 72ºC.

Hold the potatoes at this temperature for 30 minutes, removing the pan to adjusting the heat as necessary.

After 30 minutes, drain the cooked potatoes and rinse them under cold running water.

Bring a saucepan of fresh salted water to the boil and add the potatoes. Cook until extremely soft and falling apart.

Meanwhile, add the potato peelings to the milk, bring to a boil and remove from the heat. Allow to stand for 20 minutes before straining and discarding the peelings.

Drain the potatoes, return them to the pan over a very low heat to dry them out.

Put the potatoes through a ricer on to the butter in a bowl, and mix together, then put mixture through a fine sieve add the warmed infused milk and salt to taste.

Place some of the pommes purées on a plate and sprinkle with lime jelly cubes if using.

To make the lime jelly cubes, put the lime zest and juice into a saucepan and place over a medium heat. Add the sugar and bring to a simmer.

Whisk in the agar agar flakes and simmer for 4 minutes.

Blitz the mixture with a hand blender and pass through a sieve into a shallow container. Place in the fridge to fully set (this should take approximately 2 hours).

When ready to use, remove the jelly from the fridge and cut into 1 cm cubes.

Cook's Notes

Oven temperatures are for conventional; if using fan-forced (convection), reduce the temperature by 20˚C. | We use Australian tablespoons and cups: 1 teaspoon equals 5 ml; 1 tablespoon equals 20 ml; 1 cup equals 250 ml. | All herbs are fresh (unless specified) and cups are lightly packed. | All vegetables are medium size and peeled, unless specified. | All eggs are 55-60 g, unless specified.