Apocalypso, you can almost never go wrong with cumin in a Mexican dish. It’s the main non-pepper spice in chili powder, if you’re not familiar with it otherwise.
Apocalypso, where on earth are you located that doesn’t have good mexican spices? Even up here in the culinary challenged Northeast, I can get anything I can imagine… though often more expensive.
There is also always online sources, like Penzeys. Unless there is a retail Penzeys near you, which is worth going out of your way to visit.
Basic spices that would work though; chili powder, cumin, garlic, onion, dried and/or roasted chilis, paprika, nutmeg/cinnamon (in VERY small quantity. You almost don’t want to know it’s there, but something would be missing if it wasn’t. It’s actually in a lot of premade spice blends for latin cooking), black pepper, tomato powder (I love this stuff btw).
I don’t think you should really need additional spices for the queso. The chorizo itself has got you covered with hot pepper, cinnamon, black pepper, etc. I personally wouldn’t add anything, but a pinch of Mexican oregano (not Greek oregano–it’s a completely different herb) couldn’t hurt. In order of popularity, I would say the most important spices in Mexican cooking are: chile peppers, cumin, Mexican oregano, Ceylon (true) cinnamon. But, like I said, the chorizo should have you covered and I, personally, don’t think queso should have a cumin flavor to it, but you might like it.
I would put garlic far ahead of cumin as an essential ingredient in Mexican cooking. In fact cumin could be left off of the list for the most part. And not to forget hierbabuena, cilantro, cloves, epazote.
Sure. Actually, I’d put onion well ahead of anything. Cumin is more Tex-Mex/norteno, but I think it’s essential enough for a well-stocked Mexican kitchen. But now that I think about it, I probably would drop it lower down the list in terms of importance. I’m not sure I’d put mint (herba buena) as necessarily a signature Mexican flavor (at least I wouldn’t put it above cumin), although it is used often enough. Of course, good call on the cilantro and epazote. You can throw in achiote/annatto seeds to represent the Yucatan.
In any of the households where I frequently dine, my own and that of other members of the family, cumin is rarely used. You will find achiote but in terms of importance it is definitely more common in Yucatan.
Its prevalence is certainly variable, as Mexican cuisine is very diverse. I find it more common in norteno cooking, but it’s not (over)used like it is in Tex-Mex cooking. I’ll amend my statement to cumin being the key spice in Tex-Mex cooking and of secondary importance south of the border, although it is still used commonly enough there, depending on the dish and the region.