In a bowl, add in the tuna chunks, lime juice, olive oil, salt and cumin powder. Mix and let it absorb with the tuna in the fridge for 10 minutes. Adjust salt as needed.
Remove from the fridge then add in the jalapenos, onions, parsley and tomatoes. Mix everything together well.
Transfer to a serving dish, garnish with some sliced avocados, lime wedges, sliced jalapeno peppers and enjoy!
Notes
Go for canned tuna in water, don't use tuna in oil as it will be too oily.
Make sure to drain any excess liquid from the tuna.
Allow the tuna to sit in the fridge for at least 10 mins, this allows it to absorb all the flavors nicely!
Remove seeds and ribs from the jalapenos for milder peppers.
Garnish with some sliced avocados, lime wedges, sliced jalapeno peppers.
For a lovely presentation, you can put the ceviche tuna into the empty tuna can, using it as a ring mold, then invert it onto the plate. This is optional but a nice touch, especially for guests.