Earth Day Pie with Celeriac, Horseradish, Apple, Squash and Spinach Layers

Ingredients

For the celeriac layer

• 240g peeled celeriac, cut into small pieces
• 30g vegan butter
• ½ tsp salt
• ½ tsp pepper
• 1½ tsp caraway seeds

For the horseradish layer

• 4 tbsp vegan horseradish sauce

For the apple layer

• 2-3 Cox apples, cored and roughly chopped into large chunks
• 1 tbsp rapeseed oil

For the squash layer

• 200g winter squash, peeled and cut into small pieces
• 50g cashew nuts, chopped
• 50g walnuts, chopped
• 60g breadcrumbs
• 2 tbsp gram flour
• ½ tsp Marmite, mixed with 2 tbsp water
• ½ tsp fresh rosemary, chopped
• ½ tsp fresh thyme chopped

For the spinach layer

• 1 tbsp rapeseed oil
• 200g fresh spinach
• 1 clove garlic, crushed
• ¼ tsp nutmeg
• 1 lemon, zest only

For the pastry

• 1 tsp vegetarian oil or vegan butter, to grease the tin
• 400g shortcrust pastry
• 3 tbsp vegan plant-based milk, to glaze

Method

1. To make the celeriac layer: Fill a medium saucepan with water and bring to the boil. Add the celeriac and cook it for 8 minutes. Drain well.
2. Add the celeriac with the vegan butter, salt and pepper butter to a food processor. Process for a few seconds, until it becomes a rough purée with some pieces still visible. Add the caraway seeds and set the mixture aside.
3. To make the apple layer: Preheat the oven to 190°C/fan 170°C/gas mark 5.
4. Line an oven tray with non-stick baking parchment. Add the apple and drizzle over the rapeseed oil. Toss well and bake in the oven for 10 minutes. Set aside.
5. To make the squash layer: Fill a medium saucepan with boiling water and bring to the boil. Add the squash and cook for 10 minutes. Drain well and process in a food processor, until the squash becomes a rough purée.
6. In a large bowl, add the squash with the remaining ingredients and mix well. Set aside.
7. To make the spinach layer: In a large saucepan, heat the rapeseed oil and wilt the spinach for 5 minutes. Add the garlic and nutmeg and cook for 2 minutes. Add the lemon zest and set aside.
8. To assemble the pie: Grease a 15cm wide by 7cm high round loose-bottomed tin with vegetable oil or vegan butter. Roll out half of the pastry 3mm thick and use it to line the bottom and sides of the pie tin. Trim off any excess.
9. Add the celeriac layer first, followed by an even layer of horseradish, then the apple layer, nut roast layer and finally the spinach layer.
10. Roll out the second piece of pastry 3mm thick and cover the pie. Trim the pie with a knife and use a fork to seal the edges. With the trimmings, create some decorations inspired by the earth, such as trees and flowers.
11. Brush with vegan plant-based milk and leave it in the fridge for a least 30 minutes.
12. Preheat the oven to 200°C/fan 180°C/gas mark 6.
13. Remove the pie from the fridge and bake in the oven for 45 minutes. Let the pie rest at room temperature for 10 minutes before removing it from the tin.