The LH FCL in MUC serves inedible Stogel meals.
They also serve excellent 'Sohar' meals if you reserve in advance. Have had quite a few times. They will also warm them up in advance (unlike FRA) so if you have a short layover you can eat...
To OP - my advice would be to go into the city, by subway (S-Bahn). The kosher restaurant there is one of the best in Europe (if not the best..) IMO, and it is right in the city centre (few minutes walk from Marienplatz) so you can have a wander also. Lunch deals are especially good value - 2 course meal for about EUR 8. Most patrons are non-Jewish (90%!), so it has to meet 'regular' quality standards. It is open daily for lunch and dinner.
https://www.facebook.com/RestaurantEinsteinThere is also a kosher deli somewhat outside of city centre, he delivers all over Europe but I have never tried asking for delivery to airport
http://danel.koscher.net/shop/There is a chain of bakeries (over 30 branches throughout the city, not sure of closest to airport) and almost all the bread and many of the pastries is kosher - see
http://www.hofpfisterei.de/download/KoshZert20121203.pdfNote that this is German (and very healthy) bread - I love it but YMMV....There are many branches in the city centre if you go there. Details on website.
There used to be a sandwich place in the main produce market and a milchig cafe in the city centre, but these closed down unfortuneately.
Re airport itself - only options in lounge is fruit. you can but some kosher chocolates/crisps in the shops and duty-free.