Intermarche in Gaillard have a freezer full of bacon and pukka pies!
Unless you have special dietary requirements or are on a very limited budget, I'd suggest embracing the local cuisine/ingredients - ideally by shopping at one of the markets (if you're near to Geneva, go to the one at Ferney-Voltaire on Saturday mornings, and have a few oysters and a glass of wine while you're there).
As has been said, meat is expensive, but it is good quality. If it's prohibitive, enjoy the local cheese and veg, fabulous bread etc. And wine!! (although, IMHO, some Swiss wine is awful - try before you buy!)