Photo: Kris Kirkham
Preheat the oven to 220°C/gas mark 7. Toss the sweet potato wedges in 1½ tbsp oil and some salt and pepper. Put on a large baking tray and bake for 25 mins, turning once.
In a food processor, whizz the bread into crumbs. Cut the salmon into chunks and add to the processor with the spring onions, basil, lemon zest and egg white. Whizz until just combined.
Season the salmon mixture well and divide into 4 portions. Shape each into a burger. Cover and chill.
Heat the remaining oil in a large non-stick pan over a high heat. Brown the burgers for 1 min on each side, then add to the baking tray with the potato wedges and bake for the last 10 mins. Serve with the lemon wedges and crème fraîche.