I live in South Texas and huevos rancheros is everywhere and doesn't usually come with meat at all. At every restaurant I've been to it's two eggs any style, refried beans, and papas fritas--fried potato cubes, and the eggs have a ranchero sauce. Though the sauce to my knowledge usually contains chicken broth, and the refried beans contain lard, so they're not veggie friendly in that regard. As was pointed out, flour tortillas can contain lard, though that's usually the homemade ones. All the storebought ones I've seen are vegan. I prefer corn tortillas anyway--tons more flavor.
For future reference, there are several brands of soy chorizo that make a great substitute. I use it all the time for breakfast tacos. Way less grease, tons of flavor. If you have a Whole Foods, they carry Upton's tempeh chorizo that's delicious as well, if not a little pricey but then again it's at Whole Foods so there's a premium on everything.