Suya fillet burger

Preparation time

30 mins to 1 hour

Cooking time10 to 30 mins

Serves

Serves 2

This burger contains suya – a fiery spice mix popular in West Africa. If you don't enjoy very spicy food, reduce the amount of chilli powder in the recipe.

Ingredients

For the suya spice

• 4g smoked paprika

• 2g cayenne pepper

• 6g ginger powder

• 4g garlic powder

• 1g ground black pepper

• 11g onion salt

• 7g ground turmeric

• 6g extra hot chilli powder

• 1g ground uda pods (also known as selim pepper)

For the ‘suyannaise’

• 1 large egg yolk

• 4 tsp suya spice (see above)

• 2 tsp fresh lemon juice

• 125ml/4fl oz rapeseed oil

• 1-2 tsp just-boiled water

For the sweet potato fries

• 400g/14oz purple sweet potato

• vegetable oil, for deep frying

For the caramelised onions and burger

• 1 medium red onion, cut into rings

• 2 tbsp olive oil, for frying

• 1 tsp golden caster sugar

• 2 x 125g/4½oz beef fillet steaks

• ½ tsp coarsely ground black pepper

• 2 white ciabatta rolls, cut in half

• 2 tbsp ‘suyannaise’ (see above)

• 1 beef tomato, sliced into rounds

• 1 Little Gem lettuce, shredded

• 2 tsp suya spice, plus extra to taste

• 50g/1¾oz smoke-flavoured vintage cheddar cheese, grated

Method

1. To make the suya spice, put all the ingredients in a jam jar, seal and shake.

2. For the ‘suyannaise’, put the egg yolk into a medium bowl and whisk with the suya spice and lemon juice until pale. Add a little oil, whisk again. Whisk continuously adding the remaining oil gradually in a thin stream until the mayonnaise is very thick.

3. Once all the oil is combined, add the boiling water and whisk until the mayonnaise has a soft, dropping consistency. (You can also make the mayonnaise in a small food processor.) Transfer to a small bowl, cover the surface with cling film and store in the fridge.

4. For the sweet potato fries, slice the sweet potato into 2cm/¾in thin wedges. Half-fill a medium saucepan with water and bring to the boil. Add the sweet potato and cook for 5½ minutes, then drain in a sieve and leave to stand to cool and dry.

5. For the caramelised onions, save a few of the larger onion rings to serve raw inside the burger. Heat a tablespoon of the oil in a small non-stick saucepan over a low heat and gently fry the remaining onion for 6–8 minutes or until very soft and lightly browned, stirring regularly. Add the sugar and cook for a few seconds more, stirring. Set aside.

6. Preheat a deep-fat fryer to 180C. (CAUTION: hot oil can be dangerous. Do not leave unattended.)

7. For the burger, place the steaks on a board and cover with a sheet of cling film. Bash with a rolling pin or the base of a heavy saucepan until around 15mm/⅝in thick, then season with the pepper.

8. Heat the remaining tablespoon of oil in a medium non-stick frying pan and fry the steaks for 1½ minutes on each side, over a high heat or until cooked to your liking. Set aside to rest for 5 minutes.

9. Add the sweet potato to the fryer and cook for about 4 minutes or until golden-brown. Drain on kitchen paper.

10. Meanwhile, lightly toast the bread buns. Divide the bun bases between two plates. Top each one with a tablespoon of suyannaise, lettuce, slices of tomato and the reserved sliced red onion.

11. Sprinkle the rested steaks in suya spice and crumble the cheese on top. Melt with a blowtorch or place on a baking tray under a preheated hot grill until melted. Place in the bun and top with caramelised onions.

12. Serve the burgers with the hot sweet potato cubes on the side.