Mediterranean Tuna Salad

Prepare a large bowl, add Dijon mustard, olive oil, lemon juice, tuna in its own juice including the brine, salt, and pepper, and mix.

Peel the onion and slice it into rings. Core the bell pepper and, along with the cucumber and tomato, dice it into small cubes. Add all the chopped vegetables to the bowl with the tuna mixture and mix everything again.

Divide the prepared salad among 4 plates, finely crumble Balkan cheese over each portion, and serve.