Start the day before. Shake the sugar, salt and vinegar together in a jam jar until dissolved. Add the thinly sliced shallots and a slice of beetroot if you want a vivid pink colour. Add a pinch of turmeric for bright yellow onions or leave them natural. Add a clove or two if you want a bit of festive spice. Place the lid on and leave in the fridge until you need them.

Line a large sieve with muslin or cheesecloth. Place over a large bowl and spoon the yogurt into the sieve. Cover with a dinner plate and set aside overnight. You can leave it on the kitchen counter for a tangier taste or place it in the fridge. By morning the yogurt left in the sieve will be thick like cream cheese and the excess water will have drained out. Discard the water.

Fold the sumac, lemon zest, salt and pepper into the labneh. Spoon into a bowl, drizzle with a little olive oil and sprinkle with a pinch of sumac. This can all be done the day before.

Toast the bagels at the last minute and wrap in a tea towel to keep them warm, place the smoked trout, sliced avocado and a handful of salad leaves on a big platter in the middle of the table. Serve with the labneh, pickled shallots and warm toasted bagels.