Preheat the oven to 180°C Fan. Place each salmon fillet on a separate piece of foil. Drizzle with olive oil and press chopped coriander onto the surface. Add two slices of lemon on to each salmon fillet and wrap the foil around to seal.
Place the foil parcels on a baking tray and pop in the oven for 20 minutes.
In the meantime, slit pitta bread open to make 2 pockets. If you wish, you can very lightly toast the pittas to warm them through.
Spread creme fraiche inside the pitta pockets and sprinkle with some black pepper. Arrange a layer of spinach and a layer of avocado slices on top.
Once the salmon has baked, carefully unwrap the foil parcels. Remove the lemon and flake the salmon fillets into pieces. Arrange them on top of the spinach & avocado! Dig in!