Just to give on-topic response re Kosher meals on Singapore Airlines; on a recent trip I got;
From ATH-SIN in business, Stogel long-life, Say no more, as expected...
From SIN-SYD in first, Hermolis frozen - lots of food but I didn't find it very tasty (eg cod with salmon filling). Same as business class I think.
From SYD-SIN in business, Lewis's frozen, pretty good. Loads of food - 4 full meals for a 7 hour flight (they cater 2 business class meals for each of lunch and snack to allow a choice of mains at each!)
From SIN-ATH in business, Hermolis frozen - lots of food but I didn't find it very tasty. Same as from SIN-SYD with extra hot entree.
Overall not terribly impressed TBH. Have had better.
PS have also had stogel long life on Lufthansa and Thai in First, and many others in business.