Well you won't find these on any street corner in Mexico City, but you can find them in my friend's kitchen on Veracruz Street. But if he refuses to invite you in, then here's how to make them on your own.
What's in it:
1 fish fillet
1/2 avocado, mashed
manchego cheese
1/2 jalapeño
1/4 onion
1 tbs mayonnaise
1 tbs mustard
1 tbs butter
4 leaves of spinach
1 tsp dried oregano
1 tsp garlic powder
1 bolio (torta bread)
Slice onions into strips and fry with olive oil, oregano and jalapeño.
Sprinkle the fish with garlic powder and dried chives, and in a separate pan, fry in butter. Assuming you're not on a diet, cover the bolio with mayonnaise and mustard. Add a few slices of cheese and put in toaster oven until it melts. Add the spinach and avocado. Serve with a michelada and enjoy!