All Thai food is yummy, and I have long been leafing through Asian Soups, a book I once bought in Boston, with that in mind. Suzie Smith's book has stocks and spice pastes in it as well as soups, and I would gladly try nearly every recipe. All autumn I did not get round to cooking a single one. Yesterday, though, was my last exam (touch wood), so today I could make an excursion to Vii Voan in Hakaniemi with a clear conscience.
Vii Voan is an Asian grocery in Helsinki and my favourite shop, and I am happy to trawl its shelves even with nothing to buy. Today I had a shopping list. It was a pleasant few degrees below freezing outside, and I came home with fresh coriander, basil and mint, a couple of limes, some chillies and a piece of ginger in my bag. The sweet potato I had bought earlier at the K-Supermarket. It had been grown in the United States.
The base of the soup is a mild purée of oven-baked sweet potato, red onion, ginger, garlic and a litre of chicken stock. Only half of the onion, ginger and garlic goes into the purée. The other half is fried quickly in a pan, for about a minute, with the chilli, the lime zest and the meat, and once the pan is off the heat the fish sauce, lime juice, black pepper and a handful of each herb are stirred in. This herb mix is spooned on top of the purée in the bowl, and that is where the soup gets its flavour. There is no need to be alarmed by the fish sauce, even though it is a liquid made from salted, fermented fish. It is the basic seasoning of the Thai kitchen, and the whole soup takes only half a teaspoon of it.
Naturally you can make a veggie version of the soup simply by leaving out the meat, since it only goes on top of the finished soup anyway. The herb mix has to be made all the same, because the flavour of the soup depends on it.
The sweet potato is baked in the oven whole, skin and all, until a skewer goes through it easily. Depending on its size that takes anything from half an hour to an hour, which is plenty of time to slice the onion and grate the ginger. The oven makes the sweet potato sweeter still. In spite of the name, by the way, it is only a distant relation of the potato. The sweet potatoes I ate in America had always been orange, and it had never occurred to me that they came in any other colour. This one was pale under its skin, so I coloured the soup with a tablespoon of turmeric.
The result was this mildly spiced, pleasantly warming and delicious Thai soup. The purée is soft and on the sweet side, and the sharpness comes from the chilli and lime on top. On the plate the herb leaves were left floating on the surface. The soup is eaten at once, before the herbs have time to wilt in the heat.
Recipe card
Thai Sweet Potato Soup with Lamb Fillet
- serves two
- Oven 200 °C
- Baking the sweet potato 30-60 min
- Simmering the stock 15 min
You will need
| 1 | medium sweet potato |
| olive oil for frying | |
| 1 | large red onion |
| 1 1/2 | cloves of garlic, crushed |
| 2.5 cm | fresh ginger, peeled and grated |
| 1 litre | chicken stock (or a litre of water and two stock cubes) |
| (1 tbsp) | ground turmeric (if needed) |
| 1 | small red chilli, finely chopped |
| 1 | lime, the zest, grated |
| 100-200 g | chicken or duck breast or lamb fillet |
| 1/2 tsp | Thai fish sauce |
| 1 | lime, the juice |
| ground black pepper | |
| a handful | fresh coriander |
| a handful | fresh basil |
| a handful | fresh mint |
Method
- Bake the sweet potato in its skin in a 200 °C oven until a skewer goes through it easily, 30-60 minutes.
- Meanwhile peel and grate the ginger, slice the red onion into fine strips and chop the garlic finely, and divide these into two portions. You can also grate the lime zest and chop the chilli in advance.
- Cut the meat into small bite-sized pieces, cook it lightly and set it aside.
- When the sweet potato is done, take it out of the oven and leave it to cool until you can peel it.
- Sweat half of the onion, ginger and garlic in a splash of olive oil for about 3-5 minutes. Add the chicken stock and colour it with turmeric if needed, in case the sweet potato you bought happened to be the pale sort. Simmer gently for 15 minutes.
- Add the peeled and chopped sweet potato to the stock and cook for 2-3 minutes. Take the pan off the heat and blend the soup smooth once it has cooled a little. Keep the purée warm enough to serve, though.
- Heat a splash of olive oil and fry the remaining half of the onion, ginger and garlic, the chilli, the lime zest and the pre-cooked meat quickly, stirring, for about a minute. Take off the heat and add the fish sauce, lime juice, black pepper, coriander, basil and mint. Stir quickly.
- Ladle the purée straight into the bowls and spoon the meat mixture carefully on top of each serving. Eat at once.
The original recipe was written for duck, but I used lamb fillet left over from the day before. I thought it suited the soup very well. Turmeric is used only for the sake of a fine yellow colour, and can be left out without the flavour suffering in the least.
1 comment
[...] Parin päivän takainen thaibataattisosekeitto onnistui muuten mainiosti, mutta sen hailakka väri jäi kaivertamaan mieltä. Pääsin miten kuten siedettävään lopputulokseen värjäämällä valmiin keiton ruokalusikallisella kurkumaa, mutta näin saatu sävy oli kaukana siitä intensiivisestä oranssista, johon olin Amerikassa tottunut. [...]