Tuna Sandwich with Sambal and Atjar

Heat the white wine vinegar with the sugar in a saucepan and stir until the sugar has dissolved. Let it cool. Place the cucumber and onion in a jar and 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 spring onions. Slice them lengthwise and then into thin pieces. In a bowl, mix the tuna, spring onion, red onion, sambal, cilantro, 1 tablespoon of olive oil, and a pinch of salt until well combined. Soon the tuna salad onto 4 slices of bread and top with grated cheddar. Cover with the remaining slices of bread.

Brush the sandwich toaster, or frying pan with oil or butter. Cook the sandwich in the toaster, or in the pan for 2-3 minutes on each side until golden brown.

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