Start preparing the tortillas. Combine the tortilla ingredients (except the butter) in a bowl. Fold together until incorporated.
Melt the butter on a preheated pan then fry the tortillas. Make the tortillas as thin as possible by turning around the pan and spreading the batter evenly.
Make the filling for the tortillas. Sauté the minced onion in cooking oil then brown the ground beef in the oil as well. Leave for 10 minutes to cook.
Season the beef with the spices and stir for 2 more minutes for the beef to fully absorb the flavors.
Fill the tortillas with the beef. Plop in the avocado, tomato, and sour cream in the tortilla as well.