Put the chorizo into a wide frypan and heat gently with 1 tablespoon water until the fat starts to come out and the red colour is beginning to cover the base of the frypan.
Add onions, capsicum, celery and turn up to medium then fry gently until the onions and capsicum have softened. There should be enough fat from the chorizo but if the vegetables are sticking to the bottom of the frypan add 1 tablespoon water and keep stirring.
Add tinned tomatoes and bring to the boil then simmer for 10 minutes until the sauce has reduced somewhat.
Add the rosemary if using and check for seasoning; add salt and pepper to taste.
Turn heat down to gentle simmer and add turkey meat, heating it without the meat falling apart. Turn off heat and stir through creme fraiche then pour into a large rectangular casserole dish.
Meanwhile put potatoes, sweet potatoes and celeriac into a saucepan and cover with water and boil until soft. Drain then mash with butter, salt and pepper.
Spoon the warm orange mash over the turkey mixture then bake at 180 degrees C for 20 minutes to crisp the top. Serve with a green vegetable like cabbage or broccoli.