Slice new potatoes into 1cm pieces with skin on. Soak in water briefly and lightly drain. Arrange on a microwave-safe plate, cover loosely with plastic wrap, and microwave at 600W for 3 minutes until softened.

Cut the sausage into 8mm thick slices.

Place bread on a baking tray lined with aluminum foil. Add the slice of melting cheese on top, followed by the microwaved potatoes and sausage slices. Drizzle mayonnaise and sprinkle salt and pepper. Toast for 3–4 minutes until golden brown.