I bump into this issue from time to time (this photo is from Helsingin Sanomat), so I guess I have to tell my audience about it. The long rant that follows simply boils down to this: Tex-Mex is not Mexican food! The first time I saw hard-shell so-called tacos was in Europe. The only truly Mexican brand of chillies on sale here is “La Costeña”, all others are European or American copycats.
Most of the food on sale in “Mexican” restaurants outside of North America (there are honourable exceptions, but they’re few) is unknown to a Mexican, including such things as burritos (which are only found in Northern Mexico, if at all) or nachos with cheese. Those things to us are like a salmon burger would be to a Finn, or mussels with cheddar to a Belgian.
I don’t deny Tex-Mex can be good food, just please don’t call it Mexican. You have no idea how much you’re missing. The funniest thing is that now in the States you can get proper Mexican food, but in Europe we’re still stuck with the Americanised adaptation (just like the differences between rodeo and charrería).