Heat a little oil in a thick bottom pan or a non stick pan.
Add onion, ginger, curry leaves, green chilly and saute them.
When it is done, add corriander powder, masala powder, turmeric, chilly powder and salt & stir it well.
Add tuna along with the tomato sauce in it and grated carrot and stir it well to avoid lumps and heat it till all water is gone.
Check the salt and add more, if needed.
Add coriander leaves and stir.
Remove from fire and keep it aside to cool.
Spread pastry sheet on a flat surface and keep the tuna mix as a line on one side after leaving 1 cm on one side.
Roll the pastry sheet once just to cover the tuna mix.
Add another line of tuna masala mix near to the roll as a line of 1 cm width and roll it again to cover the second layer of tuna mix.
Continue putting tuna mix and rolling the pastry sheet till the whole pastry sheet is rolled as a cylinder.
Roll it tightly from the begining so that you get a smooth thin cylinder.
Cut it into small pieces of 1 cm width.
Shape it into good circles by hand.
Butter a baking tray or spread butter paper on the tray and arrange the rolls on it by keeping some space in between.
:- Usually each roll will expand bit when it is well cooked.
Bake it at 180ªC for 30 mins or till it is done.
:- Serve hot as a starter for party or as an evening snack.
:- If you use double grill oven, try to bake it with both grills on for 10 mins and then cover it with aluminium foil and bake it for 20 mins with the lower grill alone.
:- If you don`t get tuna with tomato sauce, use cooked tuna or tinned tuna after removing the salt water. add 2 chopped tomatoes to the onion masala mixture and stir it at low heat till all the water is gone and then add tuna and follow the recipe as given above.