To the heated oil, add the cumin seeds and onion. Once the onions has softened add the garlic and ginger pastes. Add the chile if you want. I have mentioned slit lengthwise, you can chop it real fine too.
Next add the spices: turmeric, coriander and chile. Allow this to cook until the raw smell of the spices becomes fragant. Add the salt and the tomatoes.
Give it all a quick stir and I let it cook on medium low. About 10-ish mins later, you will have a mostly cooked, fragrant, tomato-onion mixture.
As the final step, I add the can of tuna. Add the freshly chopped coriander leaves, stir and transfer to a serving bowl.
Serving suggestions: This goes great with rotis, or bread/buns like I did on this occasion. Adding potatoes to this mix and serving it with rice is a great combo too!