Finely dice the red onion and combine it in a bowl with the onion soup mix and evaporated milk.

Gradually add grated cheese until the mixture is thick enough to soak up most of the liquid.

Refrigerate the mixture for at least 1 hour to allow the soup mix to fully absorb the juices.

Butter slices of sandwich bread and remove the crusts from the sides, leaving the top and bottom crusts intact.

Spread the buttered side of the bread face down on a work surface with a crust at the top.

Place a generous spoonful of the cheese mixture along the bottom edge of the bread slice.

Firmly roll the bread slice from bottom to top, enclosing the cheese mixture.

Place the rolled cheese rolls on a baking tray lined with baking paper.

Preheat the oven to 180°C (350°F).

Bake the cheese rolls for approximately 10 minutes, flipping once halfway through.

Bake until the rolls are golden brown and the cheese mixture begins to ooze out slightly.

For an optional twist, dice bacon, fry it until crispy, and mix it into the cheese mixture before spreading.