4 sweet potatoes, cut into thick chips
Low-calorie cooking spray
2 large onions, cut into 1cm-thick slices, rings separated
For the burgers:
4 spring onions, very finely chopped
500g lean beef mince (5% fat or less)
2 tsp dried mixed herbs
2 tsp dried steak seasoning
1 tsp mustard powder
2 tbsp fat-free natural fromage frais
4 x 60g wholemeal rolls, halved
2 little gem lettuces, shredded
2 tomatoes, thinly sliced
Quarter cucumber, thinly sliced
1 Preheat your oven to 200C/fan 180C/gas 6. For the burgers, put the spring onions, mince, dried herbs and steak seasoning in a bowl, and season. Mix with your hands until well combined, then shape into 4 burgers. Stir together the mustard and fromage frais, and season. Put the burgers and mayo in the fridge.
1 Meanwhile, spread the chips in a single layer on a baking tray lined with baking paper. Spray with low-calorie cooking spray, season and bake for 25-30 minutes, or until soft and golden.
1 While the chips are cooking, place a non-stick griddle or frying pan over a high heat. When hot, season the onion rings, spray with low-calorie cooking spray and cook for 3-4 minutes on each side, or until tender. Remove from the pan and keep warm.
1 Spray the burgers with low-calorie cooking spray and add to the hot pan. Cook for 1-2 minutes on each side, then reduce the heat to medium and cook for a further 5 minutes, turning frequently, until cooked through. Drain on kitchen paper. Fill each roll with little gem lettuce, tomato, cucumber and a burger topped with the mustard mayo. Serve with the onion rings and sweet potato chips.