Preheat the oven to 200°C / 400°F / Gas mark 6.
Prepare a baking tray with greaseproof paper and set aside.
In a large pan, heat the oil then add the leeks, onions and season with salt and pepper.
Cook for 15-20 minutes until soft and beginning to take colour.
Meanwhile, put the spinach in a colander and pour over a kettle of boiling water.
Press out the excess liquids using a spoon.
In a food processor, add 2 slices of wholemeal bread and blitz.
Mix the breadcrumbs and cheese together.
Arrange the leek and onion mixture between 4 ovenproof dishes, then scatter with the spinach and pieces of sundried tomato.
Make a well in the middle of each dish and crack an egg in it.
Season and sprinkle with cheese and breadcrumbs.
Put the dishes on the baking tray and cook for 12-15 minutes, until the whites are set and yolks are cooked as desired.