Cut the tuna into cubes and fry it in olive oil until golden brown. Tuna cooks very quickly.
The salad is prepared in layers. Before starting to prepare, you need to combine mayonnaise with Dijon mustard. Part of the sauce should be used to grease the bottom of the plate on which the salad will be assembled.
Place coarsely chopped cucumber and halved cherry tomatoes on a bed of sauce. Salt and pepper the salad to taste.
Next, add tuna, bell peppers cut into rings, thinly sliced radishes and pitted olives. The resulting salad is ready to serve.