Mix the sour cream, eggs, oil and salt in a bowl until smooth. Combine the flour and dry yeast; add to sour cream mixture. Knead into a sticky dough. Cover the bowl; leave dough to rise in a warm place for 30 minutes.
Separate florets from broccoli stems. Peel thick stems thinly and cut into large pieces. Place the florets and stems in a steamer over a saucepan filled with 250 ml water. Bring water to a boil. Cover steamer; steam broccoli for about 8 minutes. Remove florets from steamer and set aside. Mash stems finely in a mixing bowl with the cooking water. Leave to cool.
Cut salmon slices into narrow strips. Whisk sour cream, eggs and cornflour; stir in the dill. Stir the mixture into the broccoli purée. Add the nutmeg, horseradish and lemon juice and season with salt and pepper.
Preheat oven to 200°C; grease a 28-cm ceramic fluted quiche dish.
On a lightly floured work surface, roll out pastry to line the quiche dish. Spread broccoli florets and strips of salmon over the pastry base. Pour broccoli mixture over the top.
Bake the flan for 35–45 minutes until the pastry is crisp and the filling slightly browned. Serve warm.
Try this, too…
For ASPARAGUS QUICHE WITH SALMON, make pastry as described in main recipe and use to line the dish. In place of the broccoli, use 500 g green asparagus; peel ends thinly, if necessary. Cut the asparagus into 5 cm pieces; steam over 250 ml water for 5–8 minutes until crisp-tender. Peel and dice 2 shallots. Heat 1 tbsp butter; sauté shallots until transparent. Sprinkle 1 tbsp flour over the top; sweat shallots for a few minutes over low heat. Add the asparagus cooking water, mixing it in quickly with a whisk; make sure the flour doesn't form lumps. Bring to a boil; cook until mixture starts to thicken. Remove from heat. Whisk in 3 eggs and 100 g sour cream. Season sauce with lemon juice, nutmeg and salt and pepper. Add 2 tbsp finely chopped parsley. Cut 200 g sliced smoked salmon into narrow strips; scatter over the pastry base with the steamed asparagus; pour the sauce over the top. Bake quiche as described in main recipe and serve warm.