Peel the pepper from the stalks and seeds. Cut the pulp into medium cubes.
Peel and finely chop the onion and garlic.
Pour vegetable oil into a saucepan with a thick bottom and heat it up.
Put the onion and garlic in the preheated oil, fry for 5 minutes.
Add pepper, fry for 8-10 minutes.
Peel the potatoes and cut them into 1.5 cm cubes .
Add the potatoes to the pan and fry for 5 minutes.
Pour 1.5 liters of water into a saucepan, bring to a boil, add corn and tuna along with the juice, cook for 10 minutes. Add salt and pepper to taste and let the soup brew for 15 minutes.