Cook the fish fingers according to the packet's instructions.
Meanwhile, place the creme fraiche in a bowl.
Finely dice the gherkins and add to the creme fraiche.
Pick a few leaves of fresh dill and add to the creme fraiche. Dill has a strong flavour so add it to your taste. Less is more!
Slice the lemon in half. Add a squeeze of lemon juice to the creme fraiche. Add a pinch of salt and pepper, and mix well. Set aside.
Add the frozen peas to a small pot of boiling water for three minutes. Drain and transfer to a bowl. Use a fork to mash the peas, until half are mushy and the other half are whole. Finely chop a bit of fresh mint and mix through the peas.
Remove the fish fingers from the oven once fully cooked.
Toast two gluten-free buns. Add a dollop of the gherkin creme fraiche to the bun, along with a tablespoon of mushy peas. Top with the fish fingers. Serve with slices of lemon on the side.