If you are looking at a food stand and trying to determine whether or not you should eat there, use your senses.
Look: Are other people there? If other people are eating there, there is a good chance that the food is good. Most food stands are semi-permanent, if they were terrible or made people ill, nobody would return.
Do the employees look healthy? I don’t mean do they appear to have high blood pressure or a limp, but in general are they the kind of people you wouldn’t mind sitting next to on public transportation? I always look for bandages - I refuse to eat food if someone has significant portions of her/his head or body covered in bandages. Either, they are so clumsy that you never know when a finger is going to end up in your taco (question: waiter, is this a finger in my taco - mecero, hay un dedo aqui en mi taco?) or they've got some sort of something that would kill your appetite to know about. Limes and hot sauce kill bacteria, though, so always feel free to load your food up with those, they should be provided (free of charge) with everything you can possibly order in
Does the cook occasionally reach out, grab a live cat out of a bag and throw it on the grill? Well, live cats are a-okay, it’s the ones who are grilling (planchando) the ones that are already dead you have to worry about - who knows how they died. Actually, the rumor that the meat being served to you at food stands is dog or cat is greatly exaggerated. If you’ve ever eaten at Taco Bell, the chances are that the meat you are eating at a Mexican food stand is of higher quality.
Smell: Does the food smell good? This is probably the most important aspect. If the food doesn’t smell good, don’t eat it. If you actually decide to ignore your body’s natural way of telling you not to eat something, then I’m not entirely sure that this guide book will be of any use to you. This is also an indicator of sanitation problems - rotting garbage too close for comfort for example.
Listen: Is someone selling shrimp out of a Styrofoam ice chest strapped to the back of their bicycle at 3 o’clock on a hot summer’s afternoon in a town 6 hours from the nearest possible source of seafood? If you don’t have a recommendation from someone local that you “buy shrimp from Carlos the bici guy” then probably a good idea to steer clear. If he’s selling Tamales out of that chest though, take a look and a smell. Just because something is being sold by someone who doesn’t have an “establishment” doesn’t mean it’s not good. People will enthusiastically give you directions to their favorite place, sometimes to the point where you find yourself edging away and praying for some type of distraction.
Taste: Just like at Baskin Robbins, you can always ask for a taste of something. There aren't any small, pink spoons, but it's a good way to determine the level of commitment you want to make to a particular fonda. Does the food taste good? Then eat it!
Any place you eat in
Mexicans don’t adhere to the same breakfast (desayuno) ideas that Americans have. In touristy areas or places with a lot of ex-pats, you can find a cup of coffee, scrambled eggs, and maybe even bacon. Most places though, people eat tacos or some other lunch like food for the early meal. It can take some getting used to, but now I wake up hoping for barbecue.
Food stands are either operated at large carts or in the front part of the house known as the “cochera”, what Americans would think of as a garage. If someone has a grill or large vat of frying oil out in the garage and the doors are open, it’s a food stand. Sometimes they have signs out front but sometimes they don’t. Again, use common sense – if you smell something you would like to eat and you see people cooking it or eating it outside, just ask them where you could get something like that. They’ll either invite you to eat or tell you where they got it from.