Roasted Red Pepper and Walnut Soup (Muhammara-Style)

Some of the best soups are really a good dip that learned to swim. This one began in my kitchen as muhammara, the smoky red pepper and walnut dip I cannot stop making, until one cold evening I had a little too much of it and a craving for something warm and spoonable. A splash of stock later, a new favourite was born. It keeps everything muhammara does well: roasted peppers, toasty walnuts, the sweet-sour tang of pomegranate molasses, a whisper of chilli. It is vegetarian, it is a gorgeous brick red, and it tastes far more sophisticated than the effort behind it.

From dip to bowl

Muhammara comes from Aleppo, the great Syrian city whose name is stamped on the dish in the form of its signature chilli. Traditionally it is a thick, textured dip of roasted red peppers, ground walnuts, breadcrumbs, pomegranate molasses and Aleppo pepper, scooped up with warm flatbread as part of a mezze spread across Syria, Lebanon and southern Turkey. The word muhammara comes from the Arabic for “reddened”, after its deep colour. The combination is a small masterpiece of balance: the sweetness of roasted peppers, the richness of walnuts, the bright sourness of pomegranate.

Pomegranate molasses is the ingredient that makes it sing, a thick, tangy syrup made by boiling down pomegranate juice until it reduces to a dark, sour-sweet reduction. It is used all across the Levant, in dressings, marinades and dips. Turning the dip into a soup is not remotely traditional, but it honours the flavours faithfully and gives you a way to enjoy them on a grey day. The walnuts and breadcrumbs that thicken the original dip do the same gentle work here, giving the soup body without a drop of cream.

Aleppo pepper, or pul biber, deserves a mention of its own. It is a coarsely ground, sun-dried chilli from the region around Aleppo, oily and dark red, with a fruity, raisin-like sweetness and only a moderate heat, plus a faint saltiness from the traditional curing. It is nothing like the flat burn of ordinary chilli flakes, and it is worth seeking out; a good Middle Eastern grocer will stock it, and it keeps for months. Since the disruption of the war in Syria much of the crop sold as Aleppo pepper is now grown across the border in Turkey, but the character is the same. If you genuinely cannot find it, ordinary chilli flakes with a pinch of sweet paprika get you part of the way there.

The one job worth doing properly

Char the peppers until they are genuinely blackened. That blistered skin steams off easily under a covered bowl and leaves behind soft, smoky flesh that is the heart of the whole soup. A hot grill works, or char them straight over a gas flame, turning with tongs. Do not be tempted to skip the steaming step: it is the trapped heat that lifts the skins away in sheets. If you try to peel them straight from the heat, the skin clings and you lose half the flesh with it.

While the peppers steam, toast the walnuts to wake up their flavour, then build a simple aromatic base of onion, garlic and warm spices. Everything then goes into the pot together for a short simmer before the pomegranate molasses is stirred through and the lot is blended smooth. The breadcrumbs melt away into a velvety texture. Season generously, because peppers and walnuts both want a confident hand with the salt.

Toasting the walnuts is not an optional flourish. Raw walnuts carry a flat, faintly bitter, almost soapy note that toasting drives off, replacing it with something warm and rounded. Three or four minutes in a dry pan over medium heat, shaken so they colour evenly, is enough; pull them the moment they smell nutty, because they turn from toasted to acrid in seconds and burnt walnuts will taint the whole pot. Bloom the ground spices in the oil too, giving the cumin, paprika and Aleppo pepper a minute in the hot fat before the liquid goes in. Spices are largely fat-soluble, so that brief fry releases aromas that would otherwise stay locked up and taste raw and dusty.

Getting the balance right

Take your time with the blending if you want that silky finish. A full minute in an upright blender gives a smoother, more luxurious result than a quick whizz with a stick blender, though both work. If the soup looks a touch grainy from the walnuts, a splash more stock and another blast usually sorts it out.

Add the pomegranate molasses gradually and taste as you go. You are chasing that sweet-sour balance where the soup tastes bright but not sharp, rounded but not flat. Different brands vary in acidity, so start with a tablespoon and add more only if it needs a lift. Walnuts also carry a natural bitterness, especially if they are past their best, so buy them fresh and taste one before you toast the batch.

Tips, substitutions and storage

Jarred roasted peppers are a respectable shortcut on a busy night: use about 400g, drained, though you lose a little smokiness, so bump the smoked paprika up to 1 1/2 teaspoons to compensate. If you cannot find pomegranate molasses, a tablespoon of lemon juice plus a teaspoon of honey gives a rough approximation of the sweet-sour balance, but do seek out the real thing, because a bottle lasts for ages and transforms dressings and marinades.

Breadcrumbs are the traditional thickener and they matter here too. Use stale, fresh-white breadcrumbs rather than dried; they swell and dissolve into the soup, thickening it without any floury taste and lending the same body they give the dip. If you are cooking gluten-free, a handful of cooked rice or a couple of tablespoons of ground almonds does a similar job.

For a heartier meal, swirl in a spoonful of thick yoghurt or tahini, or serve with warm flatbread for dunking, which is a nice nod to the dip it came from. A poached egg dropped into the bowl turns it into a light supper, and a scatter of toasted pine nuts alongside the walnuts adds another layer of crunch. It keeps for three days in the fridge and freezes well, ready to reheat whenever the weather turns. If you would rather keep the original dip alive too, hold back a couple of ladles before adding all the stock and let them cook down thicker; you essentially have muhammara again, ready to spread on toast. That flexibility is the joy of it: one set of ingredients, one bit of charring, and you can land anywhere from a velvety soup to a thick, scoopable mezze.

If you like a bowl that leans on nuts for body, my sweet potato and peanut stew, West African style works the same trick with groundnuts, and for something gentler on a cold night my spiced carrot and ginger soup is the one I make most.