Ingredients

140g long-grain brown rice

850g sweet potatoes, peeled and cut into small cubes

3 tbsp olive oil

1 tsp ground cumin

2 tbsp sunflower seeds

1 small red onion, very finely chopped

Thumb-sized piece ginger, peeled and finely grated

1 red chilli, deseeded and finely chopped

Small pack basil, leaves finely shredded, stalks discarded

1 ripe avocado, stoned, peeled and diced

2 tbsp lime juice

4 brioche burger buns

8 round lettuce leaves, washed and dried

25g sweet potato crisps, or ready-salted potato crisps

½ punnet mustard cress, snipped

Instructions

Step 1: Heat the oven to 200°C (180°C fan/gas mark 6). Cook the brown rice following the package instructions, then drain it in a sieve. Spread the rice out on a baking tray to steam-dry; it should be as dry as possible before combining with the sweet potatoes.

Step 2: Toss the cubed sweet potatoes with 2 tablespoons of olive oil and the ground cumin. Season with salt and pepper, then spread them in a single layer in a large roasting tin. Roast for about 30 minutes until tender and slightly colored but not too crisp. While roasting, soak the sunflower seeds in water in a cup.

Step 3: In a small saucepan over low to medium heat, warm the remaining 1 tablespoon of olive oil. Add the finely chopped onion with a pinch of salt and cook, stirring often, for 5 minutes. Add the grated ginger and chopped chilli and cook for another 5 minutes until the mixture is soft. Set aside.

Step 4: Drain and pat dry the soaked sunflower seeds, then transfer them to a large mixing bowl with the roasted sweet potatoes. Gently crush the potatoes and seeds using a masher or the back of a fork. Add the dried rice, cooked onion mixture, half of the shredded basil, and seasoning to taste. Mash together until well mixed but still a bit chunky. Shape the mixture into 4 patties, each about 10cm in diameter. These can be made up to 48 hours ahead; cover and refrigerate, and allow them to come to room temperature for 15 minutes before cooking.

Step 5: Place the patties on a baking tray lined with parchment paper. Roast in the oven for 30 minutes until warmed through and starting to brown.

Step 6: Meanwhile, make the salsa by combining the diced avocado with lime juice, the remaining basil, and seasoning to taste in a bowl.

Step 7: Heat the grill to medium and toast the cut sides of the brioche buns for about 1 minute or until golden brown. To assemble, place 2 lettuce leaves on each bun base, top with a sweet potato patty, then a spoonful of avocado salsa. Add a few sweet potato crisps and a scattering of mustard cress. Press the toasted bun tops on and serve with any leftover crisps on the side.

Tips & Variations

For extra crunch, add chopped nuts like cashews or walnuts to the burger mixture.

You can swap basil for coriander or mint in the salsa for a different herbal note.

Make the patties a day ahead to let the flavors meld and save time on serving day.

Use gluten-free buns to make this recipe suitable for gluten intolerances.

FAQs

Can I freeze these sweet potato burgers?

Yes, you can freeze the uncooked patties. Place them on a baking tray to freeze individually, then transfer to an airtight container or bag. Thaw in the refrigerator overnight before roasting as directed.

What can I serve instead of brioche buns?

You can serve the burgers in wholemeal buns, pita pockets, or even wrapped in large lettuce leaves for a lighter option.