1. To make the pastry pulse the flour, butter, salt, and pepper in a food processor until the mixture resembles coarse bread crumbs. Mix the water and ketchup, add to the flour, and pulse until the dough clumps (add more water, if needed). Gather into a disk, wrap in plastic wrap, and refrigerate for 30 minutes.

2. Preheat the oven to 400°F (200°C). Roll out a bit more than half of the dough on a lightly floured surface into a round about 1/8 in (3mm) thick. Line an 8in (20cm) springform pan with the dough.

3. Mix the sausage, onion, mustard, and nutmeg, then season with salt and pepper. Spread in the pie crust, and top with the bacon. Make 4 indentations in the sausage with the back of a soup spoon. Crack each egg into an indentation. Roll out the remaining dough. Center over the filling, trim the excess dough, and pinch the edges to seal. Score a crosshatch pattern on top and brush with a little milk. Refrigerate for 15 minutes.

4. Bake the pie for 20 minutes. Reduce the oven to 350°F (180°C), and bake for 30 minutes, until golden brown. Cool the pie before serving.