Leeks and potatoes are one of those culinary marriages made in heaven. Louis Diat’s now ubiquitous Vichysoisse, devised when he was chef at the Ritz-Carlton in the 1920, is a refinement of potage bonne femme, the simple leek and potato soup made every day in thousands of households all over France (check out my version So Simple Leek and Potato Soup). Diat remembered his mother chilling theirs with milk when he was a child growing up in Vichy. Vichysoisse is his sophisticated version. Others have refined it further by only using cream, by altering the proportion of leek to potato and onion, by adding garlic with celeriac and reducing the leeks, even eliminating leeks entirely in favour of cauliflower. It goes on and on. I make it slightly differently every time but this is my latest and the one I shall be making again; rich with flavour, not too creamy and every ingredient shining through. Good tasting news potatoes are vital; my favourite at the moment is Cornish Earlies, now widely available. So do look out for them.
Prep: 25 min plus 4 hours chilling
Cook: 25 min
1 small onion or large shallot
350g white part of leek
250g Cornish earlies, Jersey Royals or other new potatoes
750ml chicken stock
2 heaped tbsp crème fraiche
1 tbsp finely snipped chives
Halve, peel and finely chop the onion. Slice, wash and drain the leeks. Melt the butter in a spacious, lidded pan over a medium low heat and stir in onion and leek, cooking gently, stirring often while you scrape, dice and rinse the potatoes. Add the potatoes to the pan with ½ tsp salt and the stock. Increase the heat slightly, semi-cover the pan and cook until the potatoes are tender. Liquidize the soup and pass through a fine sieve. It is important not to omit the sieving. In fact it may be necessary to do it twice to achieve a perfect smoothness. Add the milk, reheat, taste for seasoning and stir in the crème fraiche. Sieve again for extra smoothness. Cool then chill for at least 4 hours. Serve sprinkled with chives.