1 - Make sure you know a bit about the company, resort(s), standard of chalets etc.

2 - Do they provide you with a set menu or will you have to provide your own?

Set menu - have a look at the menu that the chalet company provides and make sure you know how to cook the dishes on the menu. Don't talk about wanting to be creative, rather talk about how you enjoy working to guidelines and standards.

Provide your own menu - have a 6 day menu planned out and know how to cook it! Make sure it is specific to the standard the company is looking for (for example a budget company doesn't want to hear you can cook an expensive venison) .  Also, if possible, check that the ingredients you have in your menu are actually available in France. 

3 - make sure you know a bit about dietary requirements as you are bound to get these in the season (veggie, lactose and gluten free), so its likely you will be asked about them.

4- Show that you are passionate about actually cooking, not just wanting to be out on the mountain- have examples of times you have cooked for people, dishes you love making and times you have been really proud of your results. If you can, have pictures of dishes you have made to show your presentation abilities. 

5 - Give yourself a quick recap on safety and hygiene in the kitchen so its fresh in your mind (coloured chopping boards, fridge storage, stock rotation, cleaning, temperature checks). 

Lastly, be open, honest and friendly... this gets you a long way. 

Best of Luck