✔️5 banana shallots, peeled & cut into 3mm-thick slices
✔️2 garlic cloves, peeled & crushed
✔️2 tbsp olive oil
✔️Flaked sea salt & black pepper
✔️1.4kg waxy potatoes, skin on, cut into 3mm thick slices
✔️100g coconut cream, melted
✔️3 limes, 1½ tsp zest & 60ml juice
✔️200ml vegetable or chicken stock
For the aromatics
✔️150ml olive oil
✔️2 red chillies, finely sliced into rings
✔️3 garlic cloves, peeled & finely sliced
✔️2cm piece fresh ginger, julienned
✔️4 spring onions, finely sliced at an angle
Heat oven to 200C/180C fan). Put shallots, garlic, oil & 1/4 tsp salt in a 28cm ovenproof pan on a medium heat. Fry/stir until soft & deeply golden (8mins) then tip in a large bowl. Keep the pan to be used again later.
Put potatoes, coconut cream, lime juice, 2tsp salt & plenty of pepper in with shallots & mix gently. Lay 1/4 of mixture in the pan – use any smaller or broken slices of potato at this stage, save larger slices for the top – & spread out in an even layer. Lay remaining potato in a spiral on top with each slice overlapping the next. Pour on stock, cover tightly with foil & bake for 40mins.
Aromatics: Heat oil in a pan (medium heat), fry chilli, garlic & ginger for 5mins until the garlic is starting to turn golden then remove from the pan with a slotted spoon. Add the spring onions, fry for 2mins then remove. Reserve the aromatic oil.
Remove the gratin from the oven & drizzle 60ml aromatic oil over the top, return to the oven uncovered for 50mins more until the top is golden brown and crisp.
Set aside to cool for 10mins, top with the fried aromatics, lime zest & a generous pinch of flaked salt.