Gourmet Cheese Burger

• Remove the root and the dark green leafy part from the leek. Cut in half widthways.
• Take one half (double for 4p) and halve lengthways, then thinly slice. 
• Place a medium pan over medium heat with a knob of butter.
• Once hot, add the sliced leek and season with salt and pepper. Cook until softened, 6-8 mins, stirring occasionally.

• In a large bowl, combine the Worcester sauce, mustard and breadcrumbs.
• Add 2 tsp water and ¼ tsp salt (double both for 4p).
• Add the beef mince, season with pepper and mix everything together with your hands. 
• Roll into even-sized balls, then form into 1cm thick burgers, 1 per person. IMPORTANT: Wash your hands and equipment after handling raw mince.

TIP: The burgers will shrink a little during cooking.

• Place a large pan over medium-high heat with a drizzle of oil.
• Once oil is hot, fry the burgers until browned on the outside and cooked through, 10-12 mins. Turn them every 2-3 mins and lower heat if needed. IMPORTANT: The burgers are cooked when no longer pink in the middle. 
• When burgers are done, remove pan from heat.
• Place some cheese on top of each burger.
• Cover pan and set aside (off the heat) so cheese melts, 3-4 mins.

• While the burgers cook, pop the buns, cut-side up onto a baking tray.
• Warm in the oven, 2-3 mins.

• To assemble the burgers, spread a spoonful of aioli over each base bun.
• Top with the cheesy beef burger and buttered leeks then close with the top bun. 
• Serve with chips alongside.