Heat the oven to 220 C. Pat dry the fish and sprinkle with salt and pepper. In a small bowl, combine the za’atar and sumac, then sprinkle all over the top of the salmon to create a crust.

Put a large ovenproof frying pan on a medium-high heat and add 2 tablespoons of oil. Once hot, add the spinach and a pinch each of salt and pepper, and cook until just wilted – about 2-3 min. Lay the salmon skin side down on top of the spinach, drizzle the remaining 2 tablespoons of oil over the flesh side and transfer the pan to the oven for five minutes.

While the fish is cooking, whisk the tahini with a 2½ tablespoon of lemon juice, the garlic, a good pinch of salt and 100ml of water in a small bowl, until smooth and quite runny.

When the fish’s time is up, remove it from the oven, pour the tahini mixture all around (but not over) the salmon, and return the pan to the oven for another five minutes, or until the fish is cooked through and the tahini is bubbling. Spoon over the remaining tablespoon of lemon juice and serve straight from the pan.