1

Preheat the oven to 200°C, fan 180°C, gas mark 6. Put the beetroot in a small roasting tin, mist with cooking spray, scatter over the dried rosemary and season. Cover with kitchen foil and roast for 1 hour, or until tender and easily pierced with a fork. Set aside to cool.

2

Meanwhile, mist a large pan with cooking spray and cook the shallots over a low heat, stirring often, for 3-4 minutes until lightly browned. Add the garlic and cook for a further minute, then add the thyme and mushrooms. Cook the mushrooms for 5 minutes or until tender, then add the wine, cooking for 8-10 minutes, or until the wine has evaporated and the mushrooms are cooked through. Remove from the heat and stir in the walnuts. Allow to cool.

3

Microwave the spinach until wilted. Allow to cool, then, using your hands, squeeze out as much liquid from the spinach as possible. Transfer to a bowl and season well.

4

If you prepared the beetroot the day before, preheat the oven to 200°C, fan 180°C, gas mark 6 and line a baking tray with baking paper. Unroll the pastry onto the prepared tray, with a short side closest to you. Scatter the breadcrumbs over the pastry, leaving a 5cm border on all sides. Arrange the spinach in a line down the centre of the left half of the pastry strip. Arrange the beetroot in a row on top, then spoon over the mushrooms, using your hands to tightly pack the mixture around the beetroot.

5

Fold the right half of the pastry over the filling. Trim excess pastry from the ends (you’ll cut off around 50g), then press the edges with your fingers or the back of a fork to seal. Whisk the egg yolk with 1 tsp water then brush the mixture over the pastry. Cut five slashes across the top, then scatter over the sesame seeds.

6

Bake the Wellington for 45 minutes, until the pastry is crisp and turns a deep golden colour.