1/2 bunch spring onion, sliced, plus a few extra to serve
1 potato, cut into small dice
1 ltr hot vegetable stock
900g frozen petits pois
1/2 small bunch of mint leaves
85g parmesan, very finely grated
Heat the olive oil and butter in a heavy based pan. When foaming, add the spring onions and potato. Gently fry without colouring for about 5 mins. Stir in the stock, bring to the boil and simmer for 10 mins or until the potato is tender.
Stir in the peas, bring to the boil again, then cook for about 3 mins until they are just done. Remove the pan from the heat, add the mint leaves and whizz in a blender or food processor until smooth.
To make the Parmesan biscuits, heat the grill to high. Line a baking sheet with baking parchment and divide the grated Parmesan into 6 long strips. Grill for 1 min or until the cheese has melted and is lightly golden. While still warm and a bit flexible, release the biscuits from the baking parchment with a palette or cutlery knife, then cool until firm.
To serve, heat the soup and divide between 6 bowls. Scatter with mint and sliced spring onions, if you like, and serve with the Parmesan biscuits on the side.