Dice onion, and capsicum and cook in oil until soft. Add mince and cook until brown. Add in tinned tomatoes, Taco seasoning and grated carrot, and cook until boiling.
Once cooked, (I use the aluminium trays from the supermarket as its easier to just throw away) lay 2 tortillas at the bottom of the tray, cover with mince sauce, put another 2 on top and lay the remainder of the mince, then lay another 2 tortillas on top, then cover with Sour cream and cheese (You can choose to put another 2 tortillas in between the sour cream and the cheese.)
Put in the over, and cook until cheese is melted and going brown. Serve immediately, with a side salad of your choice.
This is also great for freezing. I tend to double the recipe and have plenty of left overs for the freezer which are great to take to work.