Preheat your oven to 180°C/160°C fan forced.

Taco Seasoning:

1. In a small bowl, combine all the spices and mix thoroughly until well blended. 
2. Taste the seasoning mix and adjust the level of spiciness by adding more or less cayenne pepper, according to your preference.

Mexican Stir Fry:

1. Coat the beef in half of the rice bran oil and toss it with the Mexican seasoning and crushed garlic.
2. Heat the wok over high heat and add the remaining oil. Stir-fry the beef in batches for 2 to 3 minutes or until browned. Add extra oil if needed. Once done, remove the beef from the wok and set it aside.
3. Reduce the heat of the wok to medium-high. Add a little more oil if needed and stir-fry the onion and capsicum for 2 to 3 minutes or until the onion has softened.
4. In a small bowl, combine 1 tablespoon of cold water with corn flour, mixing to form a smooth paste.
5. Return the beef to the wok.
6. Add the corn flour mixture and ½ cup of water to the meat in the wok. Stir-fry for 1 to 2 minutes or until the sauce has bubbled and slightly thickened. Add more water if too dry.
7. Season to taste with salt and pepper and stir in half of the coriander.

Tortillas:

1. Warm the tortillas in the oven for 3-5 minutes. (Or as per packet instructions.)
2. Serve the stir-fried beef with warmed tortillas, shredded lettuce, and a dollop of light sour cream. Top it off with the remaining coriander and squeeze of lime juice.