New Potato and Asparagus Soup

Continuing my personal plan for 2024, here's another recipe that I've been meaning to get round to for many years. Using new potatoes in a soup may seem a bit odd, but I remember Franco Taruschio used to make a new potato soup back in the hallowed Walnut Tree days and the estimable Simon Hopkinson has made several versions over the years. So, if two of my food heroes make it, then I have to produce my own, prosaic version. It's a different way of celebrating spring or early summer produce and you can even use the bits of asparagus that taste good but may be cheaper because they don't look their best.

As I've discovered to my cost, there are two aspects to this soup that are really important. First, don't try to ramp up the flavours by adding too many ingredients, powerful stock or spices because you'll lose the subtle flavour of the potatoes. Second, the purée stage of the soup is absolutely crucial. If you liquidise the potato mix, then the soup is likely to have an odd, sticky texture. The best way to get a soft, creamy but not gloopy result is to work the mixture through a mouli on a fine disc (or mouli-légumes or food mill - they're all essentially the same thing). Admittedly, this can be a bit of a pain and you might get away with using a hand blender with a mashing attachment on a slow speed. But don't blame me if some gloopiness ensues.

The “pesto” garnish adds an appealing flavour contrast but it does also add effort and time to the dish, so, if you're a busy person, mix some finely chopped mint leaves into a dollop of yoghurt for a quicker alternative. 

You can serve this soup hot, but warm on a sunny day in a garden is probably the best way to bring out the flavours. This will serve 2 as a lunch dish or maybe one or two more as a starter.

1 shallot,  finely chopped 
½ clove of garlic, crushed
350g new potatoes, peeled or scraped and roughly chopped 
120g asparagus, roughly chopped (reserve any nice tips for garnish)
3 good-sized mint sprigs
500ml water
200ml milk, full fat or semi-skimmed

Mint “pesto” for finishing (optional): 
    A small handful of mint leaves 
    3 smoked almonds
    Finely grated zest of ½ lemon
    Small squeeze of lemon juice
    Extra virgin olive oil 

In a pan large enough to hold all the ingredients, soften the shallot and garlic over a low to medium heat in a little olive oil. Add the potatoes, asparagus and mint and pour over the water and milk. Season with a little salt. Bring to the boil, turn down the heat and simmer gently, partly covered, until the potatoes and asparagus are very tender and in danger of breaking up. (This will vary with the type, age and size of the veg, but around 30 - 35 minutes sounds reasonable).

Meanwhile, make the “pesto” by bashing together the mint, almonds and lemon zest in a pestle and mortar. (You could use a mini blender or processor, but that could be tricky with such small amounts). Drizzle in some extra virgin olive oil until the mixture looks light enough to float on the soup, at least for a while. Stir in the squeeze of lemon juice. 

Lightly cook any asparagus tips you've set aside by simmering in some water. Reserve any leftover cooking water, in case it comes in handy for thinning the soup after the next stage.

Once the potatoes and asparagus are really tender, pass the soup through the mouli to get a silky, smooth texture. If the asparagus is a little fibrous, you might need to clean the disc at intervals, to prevent it becoming clogged. If the soup is too thick, add a little water or the reserved asparagus cooking water.

To serve, taste and adjust the seasoning, reheat the soup (either warm or hot, as you prefer), pour into warmed bowls, add a small dollop of the “pesto” (or yoghurt and mint) and any cooked asparagus tips you have.