To cook the salmon: Heat the oven to Gas Mark 4, 180°C (350°F). Brush each piece of salmon with a little oil and season with salt and black pepper. Line a baking tray with parchment paper and place the pieces of salmon on it. Place in the oven and cook for 10 minutes. To poach the eggs: While the salmon is cooking poach the eggs. Bring a large pan of water to the boil. Reduce to a gentle simmer and add the white wine vinegar and a little salt. Break two of the eggs into the water and simmer for 3-4 minutes until just cooked but still soft on the inside. Remove with a slotted spoon and drain well on kitchen paper. Repeat with the other two eggs. To make the Hollandaise Sauce: Put the egg yolks and lemon juice in a food processor and whizz until the mixture is creamy. Melt the butter in a saucepan until it is sizzling hot. Keep the processor running and slowly pour in the melted butter. Taste and season with salt and pepper.
Place the toast on plates, top with the salmon darn and poached eggs. Spoon over the hollandaise sauce and sprinkle with dill and black pepper. Serve with a mixed salad.