Slowly simmered mince with true Mexican spices give this dish its appeal. Better make plenty--they're moreish.
Heat oven to 250°F. In medium skillet, brown ground beef and onion over medium heat for 8 to 10 minutes or until beef is thoroughly cooked, stirring frequently. Drain.
Stir in the taco spice mix and add 1 1/2 cups of beef stock. Reduce heat to low; cover and simmer until the stock is absorbed (about 30-45 minutes).
Once the mince is ready, place taco shells on ungreased cookie sheet. Heat at 250°F. for 5 minutes.
To assemble tacos, layer beef mixture, cheese, lettuce and tomatoes in each taco shell. Serve with salsa; top with sour cream.
Just mix all of the ingredients together and store in an air-tight container.