Mix the avocado, mayo, and lime in a bowl and mash/stir to combine. Season with salt, cover tightly, and set aside.
Mix the cilantro and onions in a small bowl. Season with salt and set aside.
Split the meat into 4 balls. Toss the tortillas and the meat balls on a super hot griddle seasoned with peanut oil or another high smoke point oil.
Flip the tortillas, then flip the meat balls so that there is a small browned spot on the very top of the meatballs.
One by one, place a tortilla onto a meat ball and press it as thin as you possibly can with a spatula.
Cook about 3 minutes, then flip. Top with cheese and cook on the tortilla side for about 3-5 minutes to crisp the tortilla and melt the cheese.
Meanwhile, toast the buns, and spread some avo-mayo on the top and bottom buns.
double up the burgers on the grill, then transfer the doubles to the bottom buns.
Top with the jalapenos and the cilantro onion mix. Top with the top bun and serve.