Do a search for Telluride grocery.
There's two grocery stores in town and what I call "Oprah's grocery store" up in Mountain Village at the far end of the gondola(s) near the parking garage. You may find something in town, but the "goods" are up there.
You'll need to be prepared for sticker shock...
But, you'll also want to check out the farmer's market in town on Friday. Growers and ranchers come from the general vicinity, you can find fresh greens, baked goods, beef, pork, chicken, venison, elk...bring cash for this one.
One other thing, check out the rules for grilling on Warner, as no charcoal grills are allowed, see camping rules
HERE