This African-inspired 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 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
- 2 tsp fresh lemon juice
- 125ml/4fl oz rapeseed oil
- 1-2 tsp just-boiled water
For the watermelon salad
- 75g/2½oz peeled and deseeded watermelon, 1cm/½in cubes
- 75g/2½oz cucumber, 1cm/½in cubes
- 75g/2½oz feta cheese, 1cm/½in cubes
- 1 tbsp finely chopped fresh curly leaf parsley
- large pinch nigella seeds, toasted
For the sweet potato cubes
- 200g/7oz purple sweet potato
- 200g/7oz sweet potato
- vegetable oil, for deep frying
For the caramelised onions and burger
- 1 medium red onion, 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, 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 smoked cheddar, grated

Method
- To make the suya spice put all the ingredients in a jam jar seal and shake.
- 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.
- 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.
- For the watermelon salad, mix the melon, cucumber, feta and parsley in a bowl and top with toasted nigella seeds. Set aside.
- For the sweet potato cubes the sweet potato into 2cm/¾in cubes. 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.
- 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.
- Preheat a deep-fat fryer to 180C.
- 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.
- 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.
- Add the sweet potato cubes to the fryer and cook for about 4 minutes or until golden-brown. Drain on kitchen paper.
- 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.
- Sprinkle the rested steaks in suya spice and crumble the cheese on top. With a blowtorch or place on a baking tray under a preheated hot grill. Place in the bun and top with caramelised onions.
- Serve the burgers with the watermelon salad and hot sweet potato cubes on the side.