Preheat oven to 180
Heat oil in fry pan, add onion and bacon and cook for 5 min or until onion is soft. Cut the potatoes into 1cm slices.
Layer the cooked potatoes, sliced egg, onion and bacon in an ovenproof dish.
To make the cheese sauce, melt the butter in a pan, stir in the flour and pepper and cook till frothy. Gradually stir in the milk until it thickens, stir in the grated cheese.
Pour the cheese sauce over the potato mixture.
Top with some breadcrumbs if desired.
Place in the oven and bake for 20 -30 minutes or until golden.