Begin by getting the tortillas ready. In a bowl, mix all the ingredients for the tortilla, leaving out only the butter. Mix thoroughly to ensure it is well combined.
Preheat a pan and place the butter in it to melt. Use the butter to fry the tortillas. Continue to turn the pan around to spread the batter so that the tortillas will be very thin.
To prepare the filling, sauté the onion in oil. Add the beef and allow to brown. Let it cook for 10 minutes.
Add seasoning to the beef using all the spices. Allow the beef to absorb the flavors by letting it sit on heat for 2 minutes while stirring.
Use the beef to fill the tortillas. Add the sour cream, tomato, and avocado inside the tortilla.