How to Make It
Arrange chips on a large rimmed baking sheet; set aside. Preheat oven to 475°F.
Heat oil in a large skillet over medium-high. Add onion; cook, stirring often, until softened, about 3 minutes. Add beef; cook, crumbling with the back of a spoon and stirring often, until browned through, about 8 minutes. Drain and discard any excess oil.
Add beans to beef mixture; cook, stirring constantly, until heated through, about 1 minute. Use a potato masher or fork to slightly mash and break down beans. Add taco seasoning and water; cook, stirring often, until slightly thickened, about 2 minutes. Stir in salsa; cook 1 minute. Spoon beefy bean mixture evenly over chips; top evenly with cheese.
Bake in preheated oven until cheese is melted, 3 to 5 minutes. Top with desired toppings and serve immediately.