Combine flour and cottage cheese in a bowl. Add butter. Stir with a knife until well combined. Wrap in plastic wrap. Refrigerate for 1 hour.
Press dough into the base and sides of a 23cm pie dish. Cover evenly with combined onion and salmon.
Whisk eggs with cream. Pour evenly over salmon mixture. Top with grated cheese.
Bake in a hot oven (200°C) for 10 minutes. Reduce heat to moderate (180°C) and cook for a further 35 minutes or until set and golden.
