4 tbsp finely chopped fresh chives
150g/5½oz baby spinach leaves
250g/9oz plain flour
1½ tsp baking powder
1 tsp salt
1 tbsp white wine vinegar
125g-150g/4½-5½oz butter
200g/7oz crème fraîche
3 free-range eggs
4 duck eggs
425ml/15fl oz milk
150g/5½oz sliced smoked salmon, to serve