Cook a slice of onion in a little bit of oil over medium low heat until it's well browned on one side and beginning to soften. Carefully flip it over.
Place a well-seasoned, thin, thin patty of beef over the onions, pressing down gently so the onions get embedded. Continue to cook over medium-low heat until the onions are browned on the second side. This should take a couple of minutes.
Flip the entire thing over so that the beef is now in direct contact with the pan, and the onions are on top. Add a bunch of thinly sliced pickled jalapeños.
Spread the bottom bun with chipotle cream, made by pureeing a couple of chipotles packed in adobo sauce with Mexican crema or sour cream (even mayo would work great). You can also add some chopped cilantro to this if you have the inclination. Proportions here are as spicy or as mild as you'd like them to be.
Assemble and Devour
You may need two, depending on your condition.