This terrific recipe, and the (Bagel style) Bialys are from Marc Grossman’s ‘New York Cult Recipes’ book. I took the liberty of replacing the Sour Cream in his sandwich with 0% Greek Yoghurt.
Wash, and very finely slice some Fennel and / or Celery
Very finely dice the Onion
Remove the skin from the Smoked Mackerel fillets and put into a large bowl, with the chopped vegetables
Add the Greek Yoghurt, the Mayonnaise, a pinch of Salt, a crunch of Black Pepper – and give the mixture a very gentle stir
Leave the mixture in the fridge for half an hour or so
Serve inside Bialys with some Lettuce leaves and a few slices of crisp Cucumber. A simple coleslaw on the side is excellent too…