Tuna fillet without skin. It may or may not be deboned. Cut into cubes.
Heat regular oil like canola or sun flower and add to it a little sesame oil.
Fry the shallots and garlic till they are soft. Add sesame seeds.
Add the tuna chunks and then turmeric with red chilly powder.
Mix and cook till the color changes. Usually less than 5 mins.
Add some red chilly flakes.
Cover and cook on low heat for 4-5 mins.
Now add chopped tomatoes, green chilies, curry leaves, coriander powder and garam masala.
Tuna has a really strong flavor profile and these help in containing it.
Squeeze some lemon juice just before serving it hot.