Parsley sauce
Parsley sauce is a cream sauce seasoned with parsley. It is essentially a simple béchamel sauce containing chopped parsley. A variant called "liquor" is often served with pie and mash as a traditional British food, particularly in London. Parsley sauce is easy to make. Most recipes call for 5-7 ingredients and involve 3 steps.
Source: Wikipedia
Recipes
Grilled pork belly with parsley sauce (stegt flæsk med persillesovs) | SBS Food
“The Danish people recently voted stegt flæsk the national dish of Denmark in a country-wide survey. Pork belly is grilled or fried until very crisp, and served with potatoes and a rich white sauce loaded with fresh parsley. It’s a bit like a big plate...
English Parsley Sauce | Recipes | Delia Smith
Yes, it's old-fashioned nursery food, but I sometimes think that things like this need a revival. I love it with baked cod cutlets and creamy mashed potatoes, and it's also excellent with gammon, but most especially I love it with Salmon Fishcakes. The...