Vegan Leek and Smoked Tofu Gratin

Place the cashews in a small bowl and cover with cold water. Leave to soak for 4 hours at room temperature.

Preheat the oven to 200°C (fan 180°C or 400°F). Halve, trim, and slice the leeks, then wash thoroughly in cold water and drain. Mince the garlic, slice the tofu, and measure out all remaining ingredients.

Blend the drained cashews with the oat milk, nutritional yeast, cornstarch, Dijon mustard, ½ teaspoon of the salt, and a pinch of the nutmeg on high speed until completely smooth and no grainy texture remains, about 2 minutes. Set aside.

Heat 2 tablespoons olive oil in a wide oven-safe skillet or sauté pan over medium heat until shimmering. Add the leeks and cook, stirring occasionally, until softened and beginning to turn translucent at the edges, about 8 minutes, then add the minced garlic and cook, stirring constantly, until fragrant, about 1 minute.

Pour in the white wine and cook, stirring, until fully absorbed and the sharp alcohol smell has dissipated, about 3 minutes.

Add the vegetable stock, remaining salt, pepper, and nutmeg. Stir to combine, then reduce the heat to low and cook uncovered until the leeks are completely tender and most of the liquid has evaporated, about 10 minutes.

Remove the pan from the heat. Arrange the sliced smoked tofu evenly over the leeks, overlapping the pieces slightly.

Pour the cashew béchamel evenly over the tofu and leek layers, tilting the pan gently to help it settle into the gaps.

In a small bowl, combine the panko breadcrumbs, 1 tablespoon olive oil, and thyme leaves, then scatter the mixture evenly over the surface.

Bake on the middle rack until the gratin is bubbling at the edges and the breadcrumb topping is deep golden brown, about 30 minutes.

Remove from the oven and leave to rest for 10 minutes before serving — this allows the béchamel to set so portions hold their shape.