Prepare the quick-pickled radishes: combine white wine vinegar and caster sugar in a small bowl, stirring until dissolved. Add the thinly sliced radishes and set aside to pickle for at least 20 minutes.

Make the blini batter: dissolve yeast and sugar in warm water and let stand for 5 minutes until foamy. In a mixing bowl, whisk together buckwheat flour and salt.

Add the milk, egg yolk, and yeast mixture to the flour, whisking until smooth. Cover and let rest in a warm place for 15 minutes.

In a separate bowl, whisk the egg white until soft peaks form, then gently fold into the batter along with the melted butter.

Heat a non-stick frying pan over medium heat and brush lightly with butter. Drop tablespoons of batter into the pan, cooking for 1-2 minutes per side until golden and cooked through, reaching an internal temperature of 75°C. Keep warm.

Prepare the crème fraîche topping: mix crème fraîche with lemon zest and half the dill, seasoning with black pepper.

Flake the smoked trout into bite-sized pieces, ensuring any bones are removed. Note: commercially smoked trout is pre-cooked and safe to eat cold.

To assemble, place a small dollop of herbed crème fraîche on each warm blini, top with flaked smoked trout and drained pickled radish slices.

Garnish with remaining fresh dill and chives, finish with a crack of black pepper, and serve immediately.