Chipotles in adobo add major flavor to these tacos without loads of effort.
In a medium bowl, stir the tomatoes, cilantro, lime juice, and 1/4 cup of the onion; season the pico de gallo with salt and pepper.
In a large nonstick skillet, heat the oil over medium. Add the remaining onion and cook, stirring occasionally, until softened, 7 to 9 minutes. Stir in the cumin, then the beef; season. Cook, breaking up the meat with a wooden spoon, until the beef is no longer pink, about 5 minutes. Stir in the chickpeas and the chipotles and adobo sauce. Cook, stirring occasionally, until the beef is cooked through, 5 to 8 minutes more; season.
In a skillet over high heat or directly over a gas burner, toast the tortillas, turning often with tongs, until charred, about 15 to 30 seconds total on each side.
Serve the tortillas with the beef and the pico de gallo.