Method
1. If using frozen peas, place them in a small bowl and cover with boiling water for 2 minutes, then drain and rinse under cold water to keep them vibrant and just-tender.
2. Remove the skin from the smoked mackerel fillets and flake the flesh into rough bite-sized pieces, checking for any pin bones.
3. Crumble the feta cheese into small chunks and roughly tear the fresh mint leaves.
4. In a bowl, gently combine the flaked mackerel, peas, crumbled feta, and mint. Drizzle with olive oil and lemon juice, then season with black pepper (go easy on salt as mackerel and feta are already salty).
5. Lay the rye crispbreads flat on two plates side by side.
6. Spoon the mackerel mixture generously over the crispbreads, allowing some to tumble off the sides for a relaxed, rustic look.
7. Finish with an extra squeeze of lemon juice and a crack of black pepper before serving immediately.
Tip: For a creamier base, spread a thin layer of crème fraîche or labneh on the crispbread before adding the topping — it acts as a glue to hold the filling and adds a lovely cooling contrast to the smoky mackerel.