I've got to say, EK does a great job on their special meals and they aren't misers either when it comes to the SFML. I've got SFML listed in my Skywards profile as I tend to prefer sitting at the end of the plane where the seats on the T7 become pairs on the window sides and since EK starts their food service from the front you tend to miss your prefered choice when sitting there.

Let me give you an idea of what I've had on my last trip (in Y).

EK745 MLA-TIP - 2 small paninas, one with smoked slamon and greens, the other was a tuna mayo with greens, it was reasonable for a 50min hop.

EK745 TIP-DXB - Seafood mezze and a vine leaf (the stuffed vine leaf tasted a bit off and kind of ruined the rest of the appetizer). Main was a nile perch fillet with the usual veg along with the side salad.

EK384 DXB-BKK - A pretty good omelette with a creamy cheese and smoked salmon stuffing, mushroom, tomato and hash browns. Standard breakfast muffin (tasteless except for sugar and lots of it )

EK384 BKK-HKG - Was amazed with this meal, it was a Thai Green Curry with 5 good sized Tiger Prawns, veg and some nice steamed Jasmine rice, as usual the BKK kitchens did a great job.

EK381 HKG-DXB - 3 sticks of seafood kebabs, there was one salmon, prawn and another some king of white fish. Was kind of a unique idea and it was still very juicy when served.
Then the second meal was a breakfast service, which was same as the one I described earlier but this time it came with fried potato slices rather than hash browns.

EK745 DXB-MLA - Unfortunately it was another breakfast flight and I got the identical salmon omelette thing which I was rather bored of, so I just declined it as I had had something to eat in the airport anyway.

Overall I'd say its a faily good choice for someone like you heathriel and since I only found mushrooms for breakfast - an they were on the side anyways- I'm sure it wouldn't be too bad. But of course you can always specify a SFML and without mushrooms when you book.