Preheat oven to 200°C / 180°C for fan assisted/ Gas M. 6
In a medium frying pan gently sauté the onions together with the chorizo sausage for approx. 10 minutes until onions are tender. Remove from pan and drain on kitchen paper.
Divide pastry into 8 equal portions and roll out each large enough to line a 10cm individual tart tin. (If you do not have individual tins use a 23cn flan tin or similar.)
Beat together the eggs and cream and season with salt and black pepper and add a little chopped herbs if desired. Scatter the onions and chorizo in the lined tart cases and then divide the egg mixture between them.
Bake for approx. 15 minutes until the pastry is pale golden and the egg filling set and lightly golden.
Serve warm or cold, scattered with further parsley or coriander if desired.