In a bowl mix together the mince and spring onions with a little salt and pepper. Divide the mince into 6. Dampen your hands with water and form into burgers, about 1.5cm thick, pressing together well with your hands. Place 4 burgers in the fridge to firm up for 15 minutes and freeze the remaining 2 burgers for another time. Preheat an oven to Gas Mark 6, 200°C, 180°C fan. In a bowl toss the potato wedges with 1tsp paprika, 1tsp cayenne pepper, 1 tbsp olive oil and juice ½ lemon. Tip into a roasting tin, season with salt and pepper and bake for 20 minutes, then shake and cook for another 20 minutes til golden and crisped. Heat a griddle pan over a medium to high heat. Brush the burgers with a little oil and grill on both sides for 5 minutes, or til cooked to your liking. Remove the burgers from the griddle pan, carefully pouring off any excess oil, and toast the cut sides of the rolls for 2 minutes. Serve the burgers in the buns with the hot wedges on the side.