Preheat oven to 325 F. Pat dry the lamb neck and cut into pieces. Try to follow the joints. You'll need to remove the meat from the long horizontal bone, first. It's a bit tricky, but just do your best! Dredge in flour that's been seasoned with salt and pepper, set aside.
Heat oil in pot on medium-high heat, add pieces and brown in batches until each piece has a nice golden brown colour (about 3-4 minutes per side). Remove meat and place in a separate dish.
Add diced vegetables and garlic to the pot. There should be a bit of rendered lamb fat in there now, too. Sauté for a few minutes, stirring frequently.
Add pre-soaked white beans, and stir to combine with vegetables.
Season with 1 tsp each of salt and pepper, and add thyme, rosemary and bay leaf.
Add lamb pieces back to the pot, pour in chicken stock, cover with lid and set in a 325 F pre-heated oven.
Cook for at least 3 hours. Meat should be fall-off-tender. If beans are still tough, take the meat out, set aside in a dish, cover to keep warm, and cook beans for another hour.
Plate, season with a bit of salt and pepper if desired, and enjoy.
