Tuna Sandwich with Sambal and Atjar

Heat the white wine vinegar with the sugar in a saucepan and stir well until the sugar has dissolved. Let it cool. Place the cucumber and onion in a jar. Pour the vinegar-sugar mixture over them until the vegetables are fully submerged. Let it sit for at least 1 hour, but preferably for a full day.

Drain the tuna well. Remove the ends and branches of the scallions. Slice them lengthwise and then into thin pieces. In a bowl, mix the tuna, scallions, red onion, sambal, cilantro, 1 tablespoon of olive oil, and a pinch of salt until well combined. Divide the tuna salad over 4 slices of bread and top with the grated cheddar. Cover with the remaining slices of bread.

Brush the sandwich press with oil or butter, or heat oil or butter in a frying pan. Place the sandwich in the press or cook it in the pan for 2-3 minutes on each side until golden brown.

Serve the grilled cheese sandwich with pickled cucumber, onion, and a bit of extra sambal.