Preheat your oven to 220°C/200°C fan/gas mark 7.
Chop the potatoes into 2cm wide wedges (no need to peel). Pop 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, 25-35 mins. Turn halfway through.

Meanwhile, halve, peel and thinly slice the shallot. Halve the baby plum tomatoes.
Trim the baby gem, then separate the leaves. Set aside 2 large leaves per person, then thinly slice the rest widthways.
Peel and grate the garlic (or use a garlic press). Grate the cheese.

In a large bowl, combine the Mexican style spice mix, garlic, breadcrumbs, water and salt for the breadcrumbs (see ingredients for both amounts), then add the beef mince. Season with pepper and mix together with your hands.
Roll into even-sized balls, then shape into 1cm thick burgers (1 per person). TIP: The burgers will shrink a little during cooking. IMPORTANT: Wash your hands and equipment after handling raw mince.

Pop the burgers onto a lightly oiled baking tray and bake on the middle shelf of your oven until cooked through, 12-15 mins.
Meanwhile, heat a drizzle of oil in a small saucepan on medium heat. Add the shallot and cook until softened, 5-6 mins. Stir occasionally.
Transfer to a small bowl and stir in the red pepper chilli jam to make the shallot relish.

When the burgers are cooked, remove from the oven. IMPORTANT: The burgers are cooked when no longer pink in the middle.
Once cooked, carefully place the cheese on top of the burgers and pop back into the oven until the cheese has melted, 2-3 mins.
In another bowl, add the cider vinegar and a drizzle of olive oil. Season, then add the sliced lettuce and baby plum tomatoes. Toss to coat.

When everything is ready, stack 2 of the whole baby gem leaves onto each plate, then pop the cheesy burgers on top and spoon over the shallot relish.
Serve with the wedges and baby gem salad on the side. Enjoy!