Make the pickled cranberries a week or two ahead. Put the vinegar and sugar in a pan over a medium heat and bring to the boil. Stir in the remaining ingredients and continue to boil for 4 mins. Pour the mixture into a 1-litre sterilised jar, or two smaller ones, and seal well, then leave to cool. Chill in the fridge for at least a week.
Heat the oven to 200C/180C fan/gas 6. Toast the breadcrumbs in a dry frying pan for 2-3 mins until golden and toasted, then tip onto a plate and leave to cool.
Combine the breadcrumbs, thyme, sumac, lemon zest and some seasoning in a mixing bowl. Drizzle with the 5 tbsp olive oil and mix in thoroughly.
Lay a piece of baking parchment on a baking tray large enough to fit the salmon fillet. Put the salmon fillet skin-side down on top, and carefully spread the crust mixture over the top of the salmon. Don’t press the mixture down too much. Drizzle with a little extra olive oil.
Bake the salmon for 20-25 mins ideally until it is just cooked and the crust has turned a golden colour. Once cooked, transfer to a serving platter and garnish with the pistachios, some drained pickled cranberries and the parsley. Try serving with buttered greens and roast new potatoes.