Heat the 2tbsp of butter in a large saucepan over a medium heat, then add the onion, garlic and baby potatoes diced 2-3cm. Cook for 5mins until the onion is soft. Stir in the flour, then cook for a further 2 mins.
Pour in the 300ml of fish stock and bring it up to a gentle simmer. Add 300ml of white wine, cover, then simmer for 10-12 mins until baby potatoes are cooked through.
Add salt and pepper and some fish seasoning, then stir in 300ml of fresh cream. Cook for another 5 mins.
Add mix of fish and cook for another 5-10mins. Add more salt and pepper if needed. I added bit of lemon juice in the end.
Sprinkle with fresh chives or dill and serve with some crusty bread!