1.    Drain the tuna from oil, and place it in a large deep bowl. Afterwards, add the mashed potatoes, green onion, garlic, bell peppers, mayonnaise, thyme, lemon, vinegar, chili pepper, salt and black pepper; stir well then add a spoon of the crushed rusk and stir.
2.    Divide the mixture into eight equal pieces; shape the filling into rounds and then dip the filling in the egg then the flour and finally the rusk; put them in a side dish. Repeat the process until the amount ends and then refrigerate them for an hour.
3.    Heat the oil in a pan over a high heat; fry the tuna rounds for a couple of minutes on each side or until they turn golden.
4.    Place lettuce leaves on the burger rounds; afterwards, top them with the burger buns. Serve hot.

Suggestion for Serving: You can serve them with fried or grilled potatoes.