Taking camping food for Skiing in Val Thorens?

I am going on a ski trip with Wasteland Ski in January to Val Thorens and the three valleys also.

After looking at some of the restaurants in Val Thorens being quite expensive and the fact that I want to get the most out of my Skiing, I was thinking about bringing some British Army boil in the bag rations with me and a small burner and a canteen.

Will this be acceptable to do so in the resort?

I cannot seem to find anything about laws prohibiting open flame stoves etc.

My plan would be to find some quiet spot on the mountain and just pull out my stove and canteen and get a boil in the bag ration on and then have a brew. Rather than go find one of the busy cafes on the slope.

-Bonus point question!

I heard about these special chemical pouch things that you can put boil in the bag camping food in and you snap them like a glowstick and they cook the food while you have it in your pocket. I have tried googling for this but cannot find anything. Does anyone know what they are called?