Instructions

1. Dice 1/4 of a large red onion (about 1/2 cup), then thinly slice the remaining 3/4 onion (about 1 1/2 cups). Dice 2 to 3 medium vine-ripened or Roma tomatoes until you have 1 cup. Finely dice 1/2 to 1 medium jalapeño depending on heat level desired (you can remove the seeds and membranes, if desired). Halve 1 medium lime, then cut one half into wedges and reserve for serving.
2. Make the pico de gallo: Place the diced onion, tomatoes, jalapeño, and 1/2 teaspoon kosher salt in a medium bowl. Juice the lime half into the bowl and stir to combine. Taste and season with more kosher salt as needed.
3. Heat 1 tablespoon canola oil in a large skillet over medium-high heat until shimmering. Add the sliced onion and cook, stirring occasionally, until softened and deeply browned in spots, 5 to 7 minutes. Add 1 pound lean ground beef and cook, breaking the beef up with a wooden spoon into crumbles and stirring occasionally, until cooked through and browned, 5 to 10 minutes.
4. Add 1 (about 15-ounce) can pinto or black beans (do not drain) and 1/2 cup water. From 1 (1-ounce) packet or 3 tablespoons taco seasoning, set aside 1 1/2 teaspoons for the queso, then add the remaining to the skillet. Reduce the heat to low and cook, stirring occasionally, until thickened and saucy, 7 to 10 minutes. Remove from the heat and cover to keep warm. Meanwhile, make the queso while the beef and beans are cooking.
5. Tear 4 ounces sliced American cheese into small pieces. Grate 4 ounces Monterey Jack or mild cheddar cheese on the large holes of a box grater (about 1 cup). Finely chop 3 tablespoons sliced pickled jalapeños. Place 1/4 cup of the whole milk and 1 1/2 teaspoons cornstarch in a small bowl and whisk to combine.
6. Heat 1 tablespoon canola oil in a small saucepan over medium heat until shimmering. Add the reserved taco seasoning and 1/4 teaspoon kosher salt, and cook until fragrant, about 30 seconds. Add the remaining 3/4 cup whole milk and cook, whisking occasionally, until barely simmering, 1 to 2 minutes. Add the cornstarch mixture and cook, whisking constantly, until thickened and simmering for at least 1 full minute.
7. Reduce the heat to medium-low. Add the American cheese and stir until the cheese is fully melted. Add the Monterey Jack cheese in a handful at a time, stirring until fully incorporated between each handful. When the cheese is melted, remove the saucepan from the heat. Add the pickled jalapeños and 1 tablespoon jalapeño pickling brine, and stir to combine. Taste and season with more kosher salt as needed. Cover to keep warm.
8. Coarsely chop the leaves and tender stems from 1 small bunch fresh cilantro until you have 1/4 cup. Halve, pit, and dice or thinly slice 1 small ripe avocado.
9. Scatter 1 (9-ounce) bag tortilla chips on a rimmed baking sheet in an even layer. Spoon the beef mixture over the chips, then drizzle with the queso. Top with the pico de gallo, avocado, and dollops of sour cream. Drizzle with hot sauce if desired. Sprinkle with the cilantro and serve with lime wedges for squeezing.