Cut your beef and peppers into long thin strips, keep separate, and set aside. Mix together your spices in a bowl – cumin, chilli powder, paprika, salt & pepper and then pour over your beef and mix. Then add the sliced peppers and let it set for a few minutes.
Next, heat olive oil in a large wok or skillet. Add your peppers to the pan first. Once tender, add your beef. Continue to cook and stir for about 2 minutes or until the beef is cooked. Remove from heat.
Warm up your tortillas in the oven or on the skillet. Place your beef mixture in the middle and add as much sour cream as you would like. Enjoy!