In a saucepan over medium heat, combine the hot sauce, butter, vinegar, Worcestershire sauce, pepper, garlic powder and paprika. Whisk often as the butter melts and allow the mixture to come to a simmer. Once the sauce comes to a simmer, remove the pan from the heat.
In a large casserole pan, heat 1 tablespoon of oil over medium heat. Add onion, celery and carrot and cook 8-10 minutes or until the vegetables are tender. Stir in the stock, cream cheese and most of the cheddar and mix until completely melted. Add the chicken and buffalo sauce then mix everything together. Pour the mixture into the baking dish.
In a bowl, mix together the flour, suet and ½ teaspoon of salt. Use your fingertips to break up the suet then add the crumbled Stilton. Add 150ml water and mix this into the dry ingredients, bringing it together with your hands until you’ve got a good dough consistency. Roll the dough into 10 balls and top the baking dish. Scatter the remaining grated cheddar over the top and bake for 25 minutes or until the dumplings are golden and sauce bubbling.
To serve: Scatter with the chopped spring onions and serve right away.