Creamy Seaside Pie

Gather olive oil, capers, nutritional yeast, black pepper and garlic cloves.

Gather frozen peas, salt, sushi nori, vegan milk and caper brine.

Gather soy cream, wholegrain mustard, vegan butter, mixed mushrooms and parsley leaves.

Gather white wine, lemon, white onion and potatoes.

Preheat oven to 180°C.

Peel the potatoes and cut into large chunks.

Put the potatoes in a large saucepan, add enough cold water to cover and a big pinch of salt.

Turn on the heat to high and bring the water to the boil, then cover the pan partially with a lid and simmer for 15-20 minutes, until the potatoes are tender when pierced with a knife.

Drain through a colander then tip the potatoes back into the pan and set aside.

Peel and finely chop the white onion and the garlic cloves, and roughly chop the mixed mushrooms.

Warm the olive oil in a large frying pan.

Add the chopped white onion to the pan and cook for 10 minutes, until soft (cook them slowly to make sure they don't burn and to draw out the flavour).

Use scissors to cut the sushi nori into 1cm pieces and sprinkle them into the pan.

Increase the heat to medium-high and add the chopped garlic cloves and mixed mushrooms.

Cook for about 10 minutes, until soft, slightly golden and significantly reduced in size (the pan will be very full to start).

Pour in the white wine and cook until reduced by half, another 2-3 minutes.

Reduce the heat to medium and add salt, vegan milk, wholegrain mustard and nutritional yeast.

Add the capers and the caper brine from the jar.

Cut the lemon in half and squeeze in the juice, catching any pips with your other hand.

Stir everything around and continue to cook until the mixed mushrooms have soaked up around half the liquid, about 10 minutes.

Pour the soy cream into the pan and stir everything together so that the sauce has a nice creamy texture.

Add the frozen peas to the pan, folding them in so that they're well mixed.

Take the pan off the heat.

Roughly chop the parsley leaves and stir it through the mixture.

Pour the mushroom filling into the lasagne dish.

Add the vegan butter, soy cream, vegan milk, wholegrain mustard and nutritional yeast to the potatoes and mash together until thick and creamy.

Taste and season with salt and black pepper.

Spoon the mashed potatoes on top of the mushroom filling and carefully smooth it out to the edges of the dish.

Use a fork to scrape lines across the top Flake over bits of vegan butter, if you like, to help the potatoes crisp up.

Put in the oven (180°C) and bake for 20 minutes, then put under a hot grill for 2-3 minutes so it has a crispy crust with golden brown peaks.