Peel your potatoes. Cut them into slices 1cm thick. Peel the garlic cloves.
Lay the slices over the bottom of a small ovenproof dish. Place the garlic cloves evenly around.
Pour over the stock and dot over the butter. Put in the oven for 40 minutes, until the potatoes are really soft.
Cut the octopus into chunks approximately 1 inch in size. Remove the potatoes from the oven and place the octopus on top. Sprinkle with salt and pepper and baste with the buttery juice from the dish. Turn the oven up to 190 degrees Celsius and put the dish back in the oven for 10 minutes.
Remove from the oven and serve with sourdough bread on the side.