For the blinis, whisk the egg whites with an electric hand whisk until stiff peaks form when the whisk is removed.
Fold the egg yolk and flour into the egg whites.
Heat the oil in a frying pan and drop four separate spoonfuls of the blini mixture into the pan. Fry for 3-4 minutes on each side, turning with a fish slice. Remove from the pan and set aside.
For the sun-blushed tomato topping, place the chopped sun-blushed tomatoes, basil and yoghurt into a bowl. Mix well and season, to taste, with salt and freshly ground black pepper.
For the salmon topping, place the salmon, lemon juice and spring onion into a bowl. Mix well and season, to taste, with salt and freshly ground black pepper.
To serve, place the blinis onto a plate and top two of them with the tomato topping and two with the salmon topping. Garnish the blinis with whole sun-blushed tomatoes, chives and lemon wedges.