• Preheat your oven to 240°C/220°C fan/gas mark 9.
• Chop the potatoes into 2cm wedges (no need to peel).
• Pop them onto a large (lined) baking tray.
• Drizzle with oil. Season with chilli flakes (use less if you don't like spice), salt and pepper then toss to coat. Spread out in a single layer.
• When the oven is hot, bake on the top shelf until golden, 25-35 mins. Turn halfway through.

TIP: Use two baking trays if necessary.

• Peel and thinly slice the onion into rings.
• Peel and grate the garlic (or use a garlic press).

• Add the Mexican spice mix, breadcrumbs, ½ tsp salt and 2 tbsp water (double both for 4p) to a large bowl, then mix to combine.
• Add the beef mince and garlic to the bowl.
• Season with pepper then mix together with your hands. 
• Roll the mince mixture into evenly-sized balls, then flatten to make 1cm thick burger patties (1 per person). IMPORTANT: Wash hands and equipment after handling raw mince.

• Pop the burgers onto a lined baking tray.
• Bake on the middle shelf of your oven until cooked through, 12-15 mins. IMPORTANT: Burgers are cooked when no longer pink in the middle.
• Carefully place cheese on top of each burger and bake until the cheese is melted, another 3-5 mins.

TIP: The burgers will shrink a little during cooking.

• While the cheese melts, separate the brioche buns.
• Pop into the oven to warm through, 1-2 mins.

TIP: Keep an eye on them so they don't burn!

• To assemble the burgers, drizzle a little sriracha onto each base bun.
• Top with the cheesy beef burger and sliced onion. Close with the top bun.
• Serve the spicy potato wedges alongside.