Add finely chopped onion and crushed garlic cloves. Fry gently until soft.
Add the mustard seeds, turmeric, curry powder and ginger. Fry gently for a couple of minutes.
Add the chopped parsnips and stir until they are coated all over with the onion mixture.
Add vegetable stock and cashews. Bring to the boil then cook covered under medium heat for around 25mins until the parsnips are soft.
If you are making the parsnip crisps, pre-heat the oven to 180c/160c fan/gas 4.⠀Peel 2 parsnips. Cut them into very thin slices using a vegetable peeler. Spread the slices on 2 oven trays. Spray some oil over them and bake in the oven for 20-30mins until golden and crunchy. Make sure to check on the parsnip crisps from time to time so that they do not burn.
Once the parsnips are cooked, liquidise the soup with a handheld immersion blender.
Season to taste with lemon juice, salt and pepper.
Serve the soup topped with freshly chopped parsley, parsnip crisps and chilli flakes.