Place the diced avocado into a bowl.
Add a pinch of salt and use a fork to mash it up until smooth.
Add lemon zest and juice, onion, mustard, mayonnaise and Greek yoghurt, and stir until smooth.
Drain salmon, discard the liquid and add to the bowl.
Use a fork to break up the salmon and stir everything together.
Warm blinis in a pan and place on a plate.
Using two teaspoons, quenelle the salmon mixture and place on top of a warm blini.
Garnish with the herbs and serve.
