Put the sliced shallots in a small bowl with 2 tbsp malt vinegar, caster sugar and a pinch of salt. Scrunch gently with your fingers, then set aside for at least 20 minutes. They’ll soften, sharpen and turn a little glossy.

Place the potatoes in a saucepan of cold salted water. Bring to the boil, then simmer for 16 to 20 minutes until tender. A knife should slide in easily, but the potatoes shouldn’t split apart.

Drain the potatoes and leave them in the colander for 5 minutes. This pause matters. Wet potatoes steam on the tray, while dry potatoes crisp.

Heat the oven to 220°C. Brush a large roasting tray with beef dripping or vegetable oil and place it in the oven for 5 minutes. Tip the potatoes onto the hot tray, then press each one with a glass or masher until flattened but still intact.

Mix olive oil with garlic granules, mustard powder, sea salt, black pepper and celery salt. Spoon or brush the mixture over the smashed potatoes, making sure the broken edges get coated.

Roast for 30 to 35 minutes, turning once only if they release cleanly. The edges should look blistered, browned and slightly rugged. If they resist the spatula, give them another 5 minutes before moving them.

As soon as the potatoes come out, splash over the remaining 1 tbsp malt vinegar. Top with the pickled shallots, chives, parsley and lemon zest. Serve hot, while the edges still crackle.