Preheat and Prepare the Potatoes: Heat your oven to 200°C (180°C fan). Scrub the potatoes thoroughly under cold running water, then pat them bone-dry with a clean tea towel. Use a fork to prick each potato about 8-10 times — you'll hear a gentle pop as the steam escapes during baking, preventing any messy explosions in your oven.

Season the Skins: Place the dry potatoes in a large mixing bowl. Drizzle over the olive oil and use your hands to rub it into every nook and cranny of the skins — they should look glossy and feel slick to the touch. Sprinkle over the flaky sea salt and black pepper, tossing well to coat evenly. The salt will draw out surface moisture, which is the secret to that ultra-crisp finish.

Bake Until Tender: Arrange the potatoes directly on the middle oven rack, placing a baking tray on the shelf below to catch any drips. Bake for 60-75 minutes. After 45 minutes, you'll smell a wonderful toasty aroma filling your kitchen. The potatoes are ready when a skewer slides through the thickest part with no resistance, and the skin feels tight and crackling to the touch.

Prepare the Filling: While the potatoes bake, combine the softened butter, double cream, half the grated cheddar, half the spring onions, and a pinch of salt in a small saucepan. Warm over a low heat, stirring gently, until the butter melts and the mixture is smooth and steaming — about 3 minutes. The scent of melted cheese and cream will be rich and inviting.

Scoop and Mash: Remove the hot potatoes from the oven — careful, they're scorching. Use a tea towel to hold each one and slice off the top quarter lengthways. Let the steam billow out for a moment. Use a spoon to gently scoop the fluffy flesh into a large bowl, leaving a 5mm shell attached to the skin. You'll see the steam rising and the flesh will look almost snowy in texture.

Combine and Refill: Pour the warm cream mixture over the scooped potato flesh. Mash with a fork until smooth and velvety — no lumps allowed. Stir through the lemon zest and half the snipped chives. Spoon this luxurious filling back into each potato skin, mounding it slightly above the rim. The colour will be a pale, creamy gold.

Final Bake for Golden Perfection: Top each filled potato with the remaining grated cheddar and a crack of black pepper. Return to the oven for 10-12 minutes, until the cheese is bubbling and turning a deep golden brown in spots. The smell at this stage is absolutely intoxicating — nutty, buttery, and savoury all at once.

Rest and Serve: Let the potatoes rest on the tray for 3-4 minutes before serving. This allows the filling to set slightly, so it holds its shape beautifully on the plate. Transfer each potato to a warmed plate, add a generous dollop of soured cream, and scatter over the remaining spring onions and chives. The contrast of the crisp shell against the creamy, molten centre is truly spectacular.