There is, seriously, no better sauce for fried fish and boiled potatoes than sauce remoulade. There are many recipes, but most of them include mayo, chopped pickles of some sort, and at least all the Danish recipes contain a little dash of curry powder. This is mine.
1-2 tbsp capers
10 pickled onions ("syltlök", miniature pearl onions, pickled)
3-4 tbsp mayonnaise
1 tbsp mayonnaise flavored with dijon mustard & horseradish (optional)
1-2 tbsp creme fraiche
1/2 tsp curry powder
1 tbsp lemon juice
Finely chop the capers, pickled onions and cornichons. Whisk together all the ingredients, and season.