Preheat oven to Gas 6, 200°C, fan 180°C.
Grease two ovenproof ramekin dishes.
Cut out 8 circles from the bread slices, sized to fit the ramekins.
Finely dice onion and mushrooms. Heat olive oil in a frying pan and fry until softened.
Into each ramekin, place one circle of bread and top with a quarter of the onion and mushroom mixture. Add a second circle of bread, a slice of black pudding, a further slice of bread and the remaining quarter of the onion and mushroom, topping it all with the final bread circle.
In a measuring jug, whisk together the egg and milk, then pour half into each ramekin, over the bread.
Finally, top with the grated gruyere and carefully place the ramekins on a baking tray.
Bake for 25-30 minutes, until slightly risen and golden.
Serve either in the ramekins or turned out on to a plate.
This recipe can be easily altered, e.g. add bacon lardons in one layer.
It is also ideal for vegetarians by substituting the black pudding for a slice of goat log cheese.
Other vegetables can be used and layered through. It can be served in the ramekins or is also effective when turned out to expose the layers.
If turning out, make sure the savoury custard is well set, it may be necessary to add another small egg and use a little less milk.
Please note: this recipe has been created and uploaded by a member of the Tesco Real Food online community. Tesco does not test customer recipes so cannot accept responsibility for the content, validate the results or answer queries regarding them.