I know that when overseas students come to stay with us in previous years, they have dreaded "English cooking" and I hope are pleasantly surprised that I can cook better than most.
Also, if you watch the Vicar of Dibley, the old lady, Letitia Cropley, cooks appalling combinations of things like Marmite cakes, lemon curd with ham and cheese, and a bewildering concoction of chocolate with cod's roe. She was known as the Queen of Cordon Bleugh!
But, having said that, I have not noticed this in recent British detective series. Certain cooks in Agatha Christie adaptions were a bit suspect but that was usually after the war so not much choice for ingredients.
(NoteL I have just read out your OP to my OH who says no, he has not noticed this and he watches everything). British cops tend to be losers, ex-alcoholics or damaged (mentally) people. Pretty grim but salt of the earth, basically sound.