Preheat your oven to 200°C. Chop the potatoes lengthways into 1cm slices, then chop into 1cm wide chips (no need to peel).
Pop the chips onto a large baking tray. Drizzle with oil, season with salt and pepper then toss to coat. Spread out in a single layer. TIP: Use two baking trays if necessary.
When the oven is hot, roast on the top shelf until golden, 30-35 mins. Turn halfway through.

Meanwhile, cut the Cheddar in half widthways. Keep one chunk of cheese per person aside, then grate the rest.
In a large bowl, add the beef mince, season with the salt for the burger (see ingredients for amount) and pepper, then mix together with your hands.
Roll the mince into even-sized balls. Shape into 2cm thick burgers around a chunk of cheese, ensuring they’re well sealed (1 per person). IMPORTANT: Wash your hands and equipment after handling raw mince.

After the chips have cooked for 10 mins, pop the burgers onto a lightly oiled baking tray and bake on the middle shelf of your oven until cooked through, 12-15 mins. IMPORTANT: The mince is cooked when no longer pink in the middle.

Meanwhile, heat a drizzle of oil in a large frying pan on medium-high heat.
Once hot, add the bacon lardons and stir-fry until golden, 4-5 mins. While the bacon fries, halve, peel and thinly slice the onion.
Transfer the lardons to a bowl but keep the bacon fat in the pan. IMPORTANT: Wash your hands and equipment after handling raw meat. Cook lardons thoroughly.

Pop the pan with the bacon fat back on medium heat with a drizzle of oil if it's a little dry.
When hot, add the onion and sugar (see ingredients for amount). Season with salt and pepper, then fry until soft and sweet, 8-10 mins. Remove from the heat.
Meanwhile, halve the baby gem lengthways through the root, then cut each half lengthways into 3 wedges.
Mix together the soured cream, water for the dressing and cider vinegar (see ingredients for both amounts) in a small bowl. Season with salt and pepper, then set the dressing aside.

When everything is nearly ready, place the grated cheese on top of the burgers and bake until the cheese is melted, 3-4 mins. Halve the burger buns and pop onto a baking tray and into your oven to warm through, 2-3 mins. Once everything is ready, spread the BBQ sauce over each bun base and top with a burger. TIP: Scoop up any escaped cheese from the baking tray and pile on top. Spoon on the caramelised onions and finish with the bun lid. Share the baby gem wedges between your plates, cut-side up, and drizzle with the creamy dressing. Top with the bacon and as much blue cheese as you'd like. Serve the chips alongside. Enjoy!