The perfect potato cake

For this weekend I wanted a new potato recipe - something different to go with the salmon fillet I planned to cook for Sunday lunch. Gratin seemed a bit too rich and heavy, mashed potato a bit ordinary. Potato cakes or fritters would be nice, but tricky to make on time for six.
           So I started hunting through my cookbooks, beginning with Lois Daish's Dinner at Home and A Good Year. And straight away, I found exactly what I was looking for: Baked Grated Potato Cake.
"This Russian recipe makes a potato cake which is lighter than most, and is crisp on the outside and moist and tender inside."
            It looked quite easy, but as the lunch was for a special occasion and I didn't want to mess it up, I thought I'd better do a test run first. Of course I forgot to take its picture before we ate it (having a very tall, hungry son waiting for dinner to appear does tend to make me forget these things). So I waited to post this until I'd made it again for lunch today, doubling the original quantities.
            It turned out extremely well (thank goodness, because Lois herself was one of the guests). It was a bit too fiddly to make on the day itself, so I made it on Saturday and it warmed up very nicely for Sunday. It's a sort of giant latke, perfect for a tableful of people; but unlike many other grated potato cakes I've eaten and sometimes made, there's no risk of the potato being a bit undercooked.

Baked grated potato cake
From Lois Daish, Dinner at Home (1993)

2 Tbsp butter
1 medium-sized onion
750g potato (Agria work very well)
1/2 cup milk or cream (I used 1/4 cup of each)
2 eggs
salt and pepper
another 1 Tbsp butter

Butter a baking tin about 20 cm in diameter. Preheat the oven to 180C.
Finely chop the onion, melt the butter in a frying pan, and gently fry the onion for at least 10 minutes until it is golden brown.
While the onion is frying, peel the potatoes and grate them coarsely in a food processor or by hand.
Tip the potatoes into a large bowl and fill with cold water. Use your hands to swoosh the potato around and wash off excess starch. Drain the potato and wring dry in a cloth.
Rinse and dry the bowl, put the potato back into it and tip in the cooked onion and butter. Mix gently.
Separate the eggs and add the yolks to the potato mixture, together with the milk and/or cream. Season well with salt and pepper and mix gently.
Whisk the egg whites until they form soft peaks and fold them in.
Pile the mixture into the buttered baking tin and dot the top with the remaining 1 Tbsp butter.
Bake at 180C for about 40 minutes, until the top is golden brown and the potatoes are tender.

This photo is of the double-quantity version, which would easily serve eight - the original serves four.

So what else did we have? We started with crepes filled with creamed mushrooms and bacon. With the grilled salmon and potato we had a cos lettuce and avocado salad with lime dressing. For dessert, what's probably my favourite cake: Claudia Roden's orange and almond dessert cake, with pureed NZ dried apricots and cream with saffron syrup.