Awww yissss, made Nagi's tuna mornay (https://www.recipetineats.com/tuna-mornay-casserole-pasta-bake/) with the sixteen year-old and it was GOOOOOOOOD.
I really need to look up how to make white sauce without it taking an eternity though, because jesus christ it was seriously half an hour of non-stop stirring and we ended up cheating and putting corn starch in anyway.
We made the tuna mornay recipe from Recipe Tin Eats (https://www.recipetineats.com/tuna-mornay-casserole-pasta-bake/) for dinner tonight, and OMG IT WAS EPIC.
I'm not quite sure how she decided it was ten minutes of prep because it took us about fifty, with a whole lot of mess, but holy crap was it worth it! Just absolutely delicious.