Heat a skillet: Place a large skillet over medium-high heat and add a bit of oil if desired.
Sauté the onion and garlic: Add the chopped onion and garlic to the skillet and cook until they are fragrant and translucent, about 2-3 minutes.
Brown the beef: Add the ground beef to the skillet. Cook, breaking it up with a spoon, until it is browned and no longer pink, about 5-7 minutes.
Add seasoning: Stir in the taco seasoning and water. Bring to a simmer and cook until the mixture thickens, about 5 minutes.