Chard Gratin with Cream and Gruyère

Cut chard stems into 4cm lengths. Stack chard leaves, roll tightly, and slice into 3cm ribbons. Grate the Gruyère, mince the garlic, and slice the shallots.

Bring a large pot of heavily salted water to a rolling boil. Add the chard stems and blanch for 5 minutes until just tender but with some bite, then lift out with a slotted spoon and spread on a clean towel to dry thoroughly.

Return the water to the boil and blanch the chard leaves for 2 minutes until wilted and bright green, then drain, refresh under cold water, and squeeze out as much moisture as possible with your hands — this step is critical to prevent a watery gratin.

Heat the olive oil in a wide skillet over medium heat and sauté the shallots for 5 minutes until soft and translucent, stirring occasionally.

Add the garlic to the shallots and cook for 1 minute until fragrant but not coloured.

Add the blanched stems and leaves to the skillet, season with a pinch of salt and white pepper, and toss for 2 minutes over medium heat to drive off any remaining moisture. Remove from the heat.

In a medium saucepan, melt the butter over medium heat until foaming subsides, then add the flour and whisk constantly for 2 minutes to form a pale blond roux.

Add the warm milk to the roux in a slow, steady stream, whisking continuously, and cook for 4 minutes, still whisking, until the sauce thickens enough to coat the back of a spoon.

Remove the béchamel from the heat and stir in the crème fraîche, Dijon mustard, nutmeg, and half the Gruyère. Season to taste with salt and white pepper.

Heat the oven to 190°C, or 170°C for a fan oven, or gas mark 5. Butter a 28cm oval or 23 x 33cm rectangular gratin dish.

Fold the chard mixture into the béchamel until evenly combined, then pour everything into the prepared dish and smooth the surface.

Scatter the remaining Gruyère evenly over the top and bake for 30 minutes until the surface is bubbling at the edges and deeply golden with a few dark, lacy spots.

Rest the gratin for 5 minutes before serving to allow the sauce to settle and slice cleanly.