Special equipment: a 12-cup nonstick muffin tin
Preheat the oven to 375 degrees F.
Place a baking sheet in the oven to preheat for 10 minutes.
Fit a wonton wrapper into each cup of a 12-cup nonstick muffin tin, pushing the wrapper down to the bottom of the cup, and crimping as necessary so that it forms a cup.
Heat the oil in a medium skillet over medium-high heat. Add the scallions and cook, stirring until softened, about 1 minute.
Add the beef and 1/4 teaspoon salt and cook, stirring until brown, about 4 minutes. Add the taco seasoning and stir to combine.
Remove the skillet from the heat. Use a slotted spoon to transfer and transfer the taco meat to a bowl and drain off the fat.
Add the cheese, pickled jalapenos and beans to the taco meat and toss to combine. Season with salt.
Fill the wonton-lined muffin cups with the beef mixture, place the muffin tin on the preheated baking sheet and bake until the wrappers are crisp and golden brown, about 17 minutes.
Remove the nacho cups from the muffin tin and arrange on a platter.
Top with the diced avocado, pico de gallo and sour cream, and serve immediately.