Oh, soupy, I do sympathise re the little s*ds no longer eating what they used to love; DS2 turned into a food nightmare at about 2-2.5, can't remember but before that he would eat almost anything, his favourite thing was spag bol (into mouth with both hands) after that he ate almost nothing, I seem to recall he lived on peanut butter sandwiches for about 3 years but that can't be right.
For a long time all he would eat was pizza/chicken nuggets/sausages. For his whole 5th year he promised he really would eat peas on his 5th birthday but still won't (seems to be a phobia!)
He is 10 now and does have quite a good diet - loves chicken-and-asparagus-pie (shop-bought), any kind of casserole or roast, new-spuds-in-skins (hates mash for some reason, DD2 was the other way round, kids are so weird!), broccoli, DH's garlic-carrots - tolerates green beans - hates baked beans and salad. Quite likes pasta dishes again, but still most loves pizza/nuggets/sausages.
Packed lunch most days is peanut-butter sandwich, peeled quartered apple, flapjack and Frube, and he generally has a banana and assortment of cereal products after school (bread, Shreddies etc.)
Hope this helps anybody out there despairing of their child ever eating proper food again!