Sam's Portuguese-style pork and chorizo stew

500g pork, cut into large cubes

1 large or 2 medium onions, diced

2 cloves garlic, roughly chopped

1 chorizo sausage, peeled and sliced

2 or 3 potatoes, peeled and chopped in chunks

1 1/2 tablespoons smoked paprika

60ml dry sherry

60ml chicken stock

1 wine glass red wine

1 tin chopped tomatoes

1/2 tin butter beans

1 teaspoon oregano or majoram

1 1/2 tablespoon tomato puree

salt and pepper