Prepare the pickled onions by combining red onion, lime juice, apple cider vinegar, kosher salt, and sugar in a bowl. Let sit at room temperature.
Heat olive oil in a skillet over medium heat. Add diced onion and sauté for 2-3 minutes until soft. Add minced garlic and cook for another minute.
Add ground beef to the skillet, breaking it apart with a spatula. Cook until no pink remains.
Let the beef sit undisturbed for 2-3 minutes to develop crispiness, then stir and repeat as needed.
Reduce heat to medium-low and add chili powder, cumin, garlic powder, onion powder, paprika, oregano, honey, and salt. Stir to coat the meat.
Remove from heat and mix in fresh lime juice.
Serve the seasoned beef in warmed tortillas and top with desired toppings.