Start by making the sour cream. Mix together the single cream and the juice of half a lime and place into the fridge. Next, mix together the diced beef, taco spice and 1 tbsp olive oil. Allow to marinate for 20 minutes. Meanwhile, take a round cutter and cut discs out of the tortilla wraps. I usually manage to get out 4 from each wrap. Heat a large pan with a drop of oil and fry the tortilla discs on both sides. Remove from the pan and immediately fold in half to create a taco. In the same hot pan, fry the marinated beef for just 2-3 minutes. Put the tacos together, spoon a little salsa into the bottom of each and spoon in the beef. Top with diced avocado, a spoon of thick sour cream and finish off with diced tomatoes. Serve with lime wedges on the side.