Ingredients

Step by step

1. Preheat the oven to 200°C, fan 180°C, gas 6. Peel two celeriac, then trim the curved edges so that each is a straight-sided block (reserve these trimmings); dice into 2cm cubes. Toss with the garlic, marjoram, ras el hanout, oil, syrup and some seasoning. Roast for 25-30 minutes or until just tender. Set aside.
2. Peel and roughly chop the third celeriac and the trimmings from step 1. Heat 3 tablespoons of oil in a large frying pan and add the chopped celeriac. Cook for 20 minutes, covered and stirring occasionally, until caramelised and golden brown. Add 100ml water and continue to cook, covered, until tender; 8-10 minutes. Transfer to a blender and purée with the oat milk, mustard and seasoning until smooth. Cool slightly.
3. Grease a 900g loaf tin (about 10 x 20cm on the base) and line lengthways with a strip of folded and greased foil, leaving it hanging over the short ends.
4. Put the vegetable fat, salt, thyme and 150ml water in a small pan and bring to the boil, stirring until melted. Combine both flours in a mixing bowl and make a well in the centre. Pour in the hot liquid, discarding the thyme. Mix well then bring together by hand. When cool enough to handle easily, knead briefly on a lightly floured surface. Reserve a third of the pastry for the lid, wrap and leave at room temperature. Roll out the rest until large enough to line the tin, squidging it firmly into the corners, and to an even thickness all around. There should be a little pastry standing up above the edges of the tin. Pop in the freezer to firm up for 20-30 minutes.
5. Meanwhile, peel the last celeriac and then thinly slice on a mandoline or with a sharp knife, to 3-4mm thick. Take a third of the slices, sprinkle with salt and massage in. Set aside for 30 minutes to draw out excess moisture.
6. For the remoulade, first soak the cranberries in boiling water for 10 minutes, then drain. Take the remaining celeriac slices and finely slice into julienne strips. Whisk together the oil, mustard and lemon juice and combine with the julienned celeriac, cranberries, and remaining remoulade ingredients; season to taste. Chill until needed.
7. Mix together the roasted celeriac, celeriac purée, gravy granules, chopped sage, lemon zest and chilli. It should be a thick filling. Season to taste.
8. Remove the lined tin from the freezer. Pat the salted celeriac slices dry with kitchen paper then trim and press in to line the pastry case. Spoon in the celeriac filling, up to the top. Roll out the reserved pastry to slightly larger than the top of the loaf tin and make 3 round holes (use a wine cap or a cork as a guide). Brush the edge of the pastry with a little oat milk and press on as a lid. Crimp the edges, trimming off excess pastry. Brush with more oat milk to glaze and sprinkle with nigella seeds. Bake for 20 minutes then lower the temperature to 190°C, fan 170°C, gas 5 and cook for a further 45 minutes until the pastry is cooked and the celeriac filling is piping hot inside. Leave to rest for at least 45 minutes to allow the pastry to firm up before slicing.
9. For the watercress purée, heat the oilin a saucepan and gently cook theonion until soft and translucent. Add the 150ml of the vegetable stock. Bring to the boil, add the watercress and parsley. Remove from the heat, cover and leave to stand for 10 minutes to wilt in the residual heat. Blend while warm, adding a little extra stock if needed to give a smooth purée. Fold in the cornichons and season to taste; chill until ready to serve.
10. Use a serrated knife to slice the terrine into 2cm-thick slices. Serve with the remoulade and watercress purée.

Serve with

Glazed citrus-ginger carrots

Green bean casserole