Slice the chorizo into half-inch discs, putting a third of the slices to one side for later. In the casserole dish sauté the chopped onion, carrot and celery in olive oil until soft.
Fry off two thirds of the chorizo with the softened vegetables so that it caramelises and the orange, paprika-rich oil begins to run. Add the pork in handfuls and seal it off in the copper-coloured oil. It only needs to take on a little colour. As each batch is done, push it to the side to make space for the next until it has all been cooked through and mixed in with the vegetables and the chorizo. Add the tomatoes and the stock and mix in until the meat is completely submerged by the liquid.
Add the remaining slices of uncooked chorizo and stir in. Bring to a simmer. Strain the butter beans and adds them too. Put on the lid, place in the oven, and cook for 1.5 hours. To check whether the stew is ready, take out a piece of pork. It should come apart easily when tugged at with a couple of forks. If it’s not yet completely ready, just return to the oven for 20 minutes and check again. If the liquor is a little thin, put the casserole back on the hob without the lid, bring to a gentle boil and reduce the sauce. The stew can easily be prepared ahead of time, and quickly reheated when you need it. It’s even better on day two, and it lends itself to being made in even larger volume.
