1. Preheat the oven to 200C.
2. Squeeze all of the liquid from the potatoes. You can do this by squishing piles of it between your hands, or squashing down into a sieve. The way I do it is to pile it all into a clean muslin cloth, twist it together into a ball and press the liquid out.
3. Stir in the mustard, beaten eggs, plenty of salt and black pepper.
4. Brush 2 muffin trays (24 holes) with the melted butter and pour the rest into the potato mixture and stir.
5. Divide the mixture between the tins, pressing down into each muffin hole.
6. Bake for about 20 minutes or until golden and crisp.

Make the dressing

1. Stir together the dill/lime mustard and the greek yoghurt. Set aside.

To serve

1. When the rosti are cooked, allow them to stand for 5 minutes, before loosening the edges with a round ended knife and 'popping' them out.
2. Top with slices avocado, a squeeze of lime, followed by smoked salmon and the yoghurt dressing. Sprinkle with fresh dill.