For the labneh
- 450g organic full-fat goat’s milk yogurt (we like St Helen’s Farm, widely available)
For the soup
- 30g butter
- 1 tbsp olive oil
- 1 onion, finely chopped
- 2 leeks, sliced, white part only
- 2 garlic cloves, sliced
- 3 floury potatoes, such as king edward, chopped
- 1 litre good quality fresh vegetable stock, or 500ml chicken stock mixed with 500ml water
- 300g watercress
- Squeeze lemon juice (optional)
For the spiced oil
- 1 tsp cumin seeds
- 1 tsp fennel seeds
- ½ tsp nigella seeds
- 50ml extra-virgin olive oil
You’ll also need
- 2 x muslin squares and kitchen string
- To make the labneh, put the yogurt and a pinch of salt in a large double-thickness square of muslin and tie the corners together with string. Loop the string over a wooden spoon handle, then balance the spoon over a large mixing bowl in the fridge so the bag is suspended with a good gap below. Chill for at least 12 hours (see make ahead) – the liquid from the yogurt will drip into the bowl. When the yogurt has the consistency of cream cheese, remove it from the bag and keep chilled in an airtight container.
- Heat the butter and olive oil in a heavy-based heatproof casserole or large pan over a medium-low heat. When the butter is foaming, add the onion, leeks and garlic and gently cook for 5 minutes or until soft, stirring occasionally.
- Add the potatoes and stock, then bring to a simmer. Cover and cook for 15 minutes or until the potatoes are tender.
- Meanwhile, make the spiced oil. Gently warm the spices in a small frying pan over a medium heat for 1 minute, then add the extra-virgin olive oil and cook for 1 minute or until fragrant. Set aside.
- Add 100g of the watercress to the soup and cook for 2 minutes. Remove from the heat, then blend with a stick blender, adding the remaining watercress a handful at a time as you do so (see tip). Taste and season; add a little lemon juice if needed.
- To serve, ladle into warmed bowls, then add a dollop of labneh to each and swirl over a little spiced oil, making sure you have a mixture of the spices. Drizzle the remaining spiced oil over the rest of the labneh for people to help themselves.
- Whizzing the watercress in batches keeps the soup a fresh green colour.
- Make the soup the day before and keep in the fridge, then reheat to a rolling boil when ready to eat. Or freeze for up to 1 month in a sealed container. The soup will lose a little vibrancy, so you’ll need to season again before serving. You can start making the labneh up to 3 days ahead – the longer you drain it, the thicker it will become.
- A fruity, unoaked off-dry white, such as New Zealand riesling.