Cook the rice accordingly to the package. Let it cool down.
Pour away the oil from the can with the tuna and pour the tuna in a big bowl.
Cut the tomatoes in small pieces and add to the tuna.
Pour away the liquid from the can with corn kernels and add the corn in the big bowl.
Add the spices and olive oil and mix well.
Place in the fridge for minimum 1 hour or if possible, over the night.