Meanwhile cook the rice according to the instructions on the packet.
Fry the tuna in a saucepan and add the onions for about 1 minute afterwards. Leave the tuna and onions in the saucepan and move them to the edge so that there is room for the vegetables. Add the vegetables and fry in the olive oil. Season with paprika powder and salt. Add the chopped tomatoes and curry paste.
Season everything to taste and serve with the rice.