016 Greek Fasolada Beans

016 Greek Fasolada Beans - Spring 5 tbsp extra virgin olive oil plus a drizzle for serving 1 small red onion, diced 1 stalk celery, chopped into small chunks 1 large carrot, peeled and chopped into discs, then discs halved 1 400g tin chopped tomatoes 1 tsp dried oregano (or a generous handful of fresh flat-leaf parsley) ⅛ tsp fine sea salt 1 400g tin of white butter beans, rinsed (or any tinned beans you like) Ground black pepper to taste 100g feta, crumbled