Tip the peas and potatoes into a large saucepan, then pour in the stock. Bring to the boil and simmer for 10 mins, until the potato chunks are tender. Meanwhile, grill the fish fingers as per pack instructions until cooked through and golden. Cut into bitesize cubes and keep warm.
Take a third of the peas and potatoes out of the pan with a slotted spoon and set aside. Blend the rest of the soup until smooth, then stir in the pesto with the reserved vegetables. Heat through and serve in warm bowls with the fish finger croûtons on top.
The best pesto?Fresh pesto from the chiller cabinet has the best flavour. Pep up storecupboard pesto with a splash of olive oil and a grating of parmesan.