Hamburgers en Croute

I heard Tim Anderson describe a variation on beef Wellington on The Kitchen Cabinet and thought I'd give it a go.

Ingredients
400 g mince (I used beef, but chicken or pork would work too)
250 g mushrooms, finely chopped
An onion, finely chopped
2 tbsp spicy tomato ketchup
4 rashers of bacon
4 slices of cheese (I used raclette with flecks of truffle)
Salt and pepper
Butter and oil
Puff pastry (I made my own, but a pack of ready made will be fine)
1 egg, beaten

Method

1. Make the pastry and chill for an hour.
2. Fry the onions in a mixture of butter and oil until lightly golden, season with salt and pepper, then add the mushrooms and cook for a couple more minutes. Set aside to cool.
3. Mix the mince, mushrooms, onion and ketchup, and form into 4 patties.
4. Roll out the pastry and cut eight 20 cm circles (I use a soup plate as a template) then return the pastry to the fridge for 30 minutes.
5. Heat the oven to 220C and line oven trays with silicone mat.
6. Lay out 4 pastry circles on the oven trays, top each with a pattie, a rasher of bacon folded to fit and a slice of cheese.
7. Brush the edges of the loaded pastry circles with egg wash then top with the remaining pastry circles.
8. Pinch the edges of the pastry to seal them.
9. Cut a vent in the top, and brush the tops with egg.
10. Bake for 30 minutes.
11. Serves 4, with a side salad.

Yum