KLM are fine they had a rice dish avaiable on the plane and noodles at another meal break which my wife thought were ok. But It is worth taking some snacks as keith says just incase they run out of rice meals when they reach you but we were near the end of the line and had Rice avaiable.
My Wife iked the selection of flims avaiable and found the staff very friendly but very Tall!!!
Make sure you get to the airport early for checkin KLM are quite efficent compared to some of the other airlines, but you still have to go though the passport control and all the checks which can take time sometimes.
I hope you have a safe and plesant Flight to the UK :-)