1. To make the labneh (yogurt cheese), stir the salt, garlic and pepper into the yogurt. Lay a 40cm double layer of clean muslin flat and spoon the mixture into the centre. Gather the edges and tie with string. Hang over a bowl in the fridge overnight to drain – it will firm up to become more like a fresh cheese.
2. Preheat the oven to 200°C, gas mark 6. Scatter the hazelnuts on to a baking tray and roast in the oven for 5-8 minutes until golden. Remove and cool completely, then tip into a clean, dry tea towel and rub the skins off.
3. Toast the sunflower, coriander, cumin and nigella seeds, and the peppercorns in a dry pan for 2 minutes until fragrant and golden, then remove from the pan and cool. Tip into a pestle and mortar, and grind to a coarse powder.
4. Toast the sesame seeds until golden, and set aside to cool. In a food processor blitz the cooled hazelnuts finely, then tip into a bowl with the ground seeds and peppercorns. Add the toasted sesame seeds and combine. Stir in the salt and set aside.
5. Toast slices of the seeded sourdough. Top with some nuggets of labneh, cover with sliced avocado then scatter over the dukkah. The dukkah
can be kept in a jar in the fridge for 2 weeks.