For the pastry:
1. In a food processor blend the flour, butter and salt until the mix resembles breadcrumbs. Add the water and egg. Mix until it becomes a dough. Wrap in cling film and rest for 1 hour.
2. Roll the pastry into a greased tart ring 28cmx 4cm and blind bake for 20-25 minutes at 180°C remove blind baking and bake for a further 5 minutes for a golden brown base. Brush with egg yolk.
For the filling:
1. Mix the cream, milk, eggs, yolk, then add the onions and thyme. Set to the side.
2. In a food processor blend the black pudding until it becomes a pate.
3. Separate into two and roll each piece out separately in cling film enough to cover the pastry base.
4. Lay one of the black pudding rounds in the pastry then cover with 10 slices of the cooked bacon. Spinkle with half the cheese.
5. Next, ladle over with the cream, cheese and onion mix. Repeat this process and then cover with the rest of the cheese.
6. Bake in a pre heated oven 160°C for 40-45 minutes until set. Finish under a hot grill to crisp up the cheese.