I really enjoy McCall, but this is the first year in about 6 I have not been....yet. Your question is not as simple as it seems. Some of my very favorites have closed or received scathing, downhill reviews lately. The more popular places I find mediocre. Good restaurants seem to come and go pretty quickly, so recommendations are iffy. I believe staffing is very difficult in McCall, so patience is required. One word of advice if you go to the brewery, when the server suggests the hamburger…get the hamburger!! I made that mistake once and only once, but the burger is good. Lardos is for drinking beer, especially if you like a lot of beer, but not for great food. The following site may be of help for more Chowish pursuits. http://www.mountainsofexperience.com/...
I passed through McCall around the end of May when it was still emerging from winter snows. The state park had had to cancel all of the Memorial Day reservations due to remaining snow. My impression was that McCall revolves around lake side vacation homes. I can see where getting good restaurant staff could be a problem. Still there should be a number of places that cater to vacationing families who don't want to cook for themselves.
I looked for a Mexican style place that I found on the web (south around the airport), but didn't find it. But since we were camping, I didn't put a lot of effort into that search. Grocery shopping was good for the size of the town (Paul's).