Melt the butter in a large pan, then add the onions. Season with salt and cook on low-medium heat for 20 minutes or until the onions are very soft – stir regularly.
Once the onions are nice and soft and have started to go golden increase the heat to medium heat and add the apple cider. Cook for 5-10 minutes until the liquid has absorbed. Set aside.
In a blender, combine the butter beans, lemon juice, 40ml olive oil, water, and season with salt. Blend until it’s a fine puree.
Pour the butter bean puree into a pot and gently heat through.
In another pan, add the left-over olive oil and pan-fry the slices of black pudding. Turn the slices are 2.5 minutes on each side.
Reheat the onions and puree to be hot for serving.
To assemble, serve a dollop of the bean puree into the middle of the plate then spread it into a neat circle. Top with the cider braised onions and 6 pieces of black pudding. To garnish gently arrange several pieces of apple on top and serve.