Place the yogurt and salt in a large mixing bowl and stir until thoroughly combined.
Line a colander with a clean damp tea towel or several layers of muslin cloth. Position the colander over a large bowl to catch the liquid.
Pour the yogurt mixture into the lined colander.
Gather the cloth around the yogurt and secure it tightly with kitchen string or an elastic band.
Transfer to the refrigerator and allow the yogurt to drain for 24 hours. During this time, excess whey will separate, leaving behind thick and creamy labneh.
Once drained, transfer the labneh to a clean bowl.
Stir in the crushed garlic and Aleppo pepper, if using.
Spread the Herbed Labneh onto a large serving platter. Use the back of a spoon to create a shallow well in the center.
Drizzle generously with extra virgin olive oil.
Sprinkle over the lemon zest and za'atar.
Scatter the dill, mint, and parsley across the surface.
Arrange the olives, tomatoes, cucumbers, radishes, and watercress attractively over the top.
Serve immediately with fresh sourdough bread for dipping and scooping.