I have tried many ways of cooking potato cakes but getting that right combination of crisp outer layer and cooked but still firm centre has often eluded me.
Now after much research, and many fried dinners, I have found a method that so far, has produced a perfect rosti every time.
The star of the show, of course, is the potato. A waxy variety, like Maris piper or Désirée, is a must. Having less starch than a floury variety, they will hold their shape and won’t break down to a mash when cooked.
Salting the potatoes after grating and before cooking will remove even more starch resulting in a firm, crunchy cake rather that a limp, soggy looking pancake.
The recipe below makes one large rosti for a rather hungry person or will serve 2 people as part of a meal
POTATO CAKE ROSTI-STYLE
350-400 g waxy potatoes
scant ½ tablespoon fine salt
pepper to taste
1 small onion (optional)
1 tablespoon oil
25 g butter
Peel and grate the potaoes using a large hole grater, a box grater works well. Grate the onion, if using, and mix with the potatoes in a bowl. Season with the salt and some pepper and leave to stand for a few minutes.
Melt half of the butter with the oil in a large, heavy frying pan over a moderately high heat. You can test if the pan is hot enough by dropping in a shred of grated potato, it should sizzle nicely.
Take handfuls of the potato and onion mixture and squeeze out most of the moisture, adding them to the frying pan as you go. Reserve 2 tablespoons of the starchy liquid.
Spread the potatoes into a circle about 2 cm deep, pressing down gently with a spatular or fish slice. Sprinkle the reserved starch water over the top.
Reduce the heat to moderate and cook to rosti for 8 – 10 minutes until the underside is firm and set. If the rosti moves with out breaking up when you jiggle the pan then it should be firm enough to turn over.
Place a plate on top of the pan and carefully turn the whole thing over so that the rosti is on the plate with the cooked side on top. It should be golden brown and crisp. Return the frying pan back to the heat and add the remaining butter. When the butter has melted, gently slide the inverted rosti back into the pan and fry for a further 8-10 minutes. Serve immediately.