Heat oil in a skillet over high heat. Add ground beef. Stir fry, breaking up the pieces with a spatula, for about 7-10 minutes, until the beef is browned and moisture has evaporated.
Stir taco seasoning into the ground beef until well combined. If you like, you can also add 1/4 cup of water when adding the seasoning and let it simmer a bit.
Meanwhile, combine all remaining ingredients in a large bowl. Add the ground beef. Toss everything together.