Tortillas. Prep your tortillas (the meat cooks quickly). If using my low carb tortillas, be sure to wrap them in a slightly damp kitchen towel as you prep the filling (to keep them pliable and soft).
Saute. Heat oil (2 tablespoons) in a large skillet over medium heat. Once shimmering. Add the onion (1 cup) and saute until it softens and just begins to brown, 5-8 minutes. Stir in taco seasoning (3 tablespoons) and cook for 2-3 additional minutes to toast the spices, you'll know they're done once they become fragrant.
Meat. Add turkey or beef (1 pound), and break up with your spoon as it cooks and slightly browns. Cook until no longer pink. Add the salt (1 teaspoon), pepper (1/2 teaspoon), tomato sauce (8 ounces), and apple cider vinegar (1 1/2 teaspoons), and give everything a stir. Simmer until the sauce thickens to coat the meat, 4 minutes. Taste and adjust seasoning to your liking.,
Serve. Scoop the meat into your tortillas, and cover with your toppings. Enjoy!