1. Preheat oven to 150°C.
2. Rinse the beans and place into a suitable ovenproof dish (ideally cast iron). Reserve the lemon juice, zest, duck eggs & the rapeseed oil. Add all the other ingredients to the beans, and stir through.
3. Cover with a sheet of baking parchment and double wrap tightly in foil. Place into the oven for approx. 1 hour.
4. Slice off both ends of the sourdough and blitz into breadcrumbs using a food processor. Combine with lemon zest, 1 tbsp rapeseed oil and a pinch of salt and pepper.
5. Remove the beans from the oven, add the lemon juice & stir well. Return to the oven for a further 15-20 minutes to reduce to desired consistency.
6. Remove once more and discard the foil. Sprinkle over the breadcrumb mix and return to the oven for a final 10 minutes. Remove from the oven and allow to rest.
7. Toast the sourdough under a hot grill and fry the duck eggs in 1 tbsp rapeseed oil (or poach for a healthier alternative).
8. Serve the beans topped with the egg and a slice of toasted sourdough.