Line an 8x8-inch pan (20x20 cm) with parchment paper, leaving overhang. (Assumption)
Melt the white chocolate melts/discs until smooth (microwave in short bursts, stirring between, or use a double boiler).
Stir in the oil until glossy and fully combined.
Fold in marshmallows, glacé cherries, pistachios, and coconut until evenly coated.
Spread into the lined pan and press into an even layer.
Top with reserved glacé cherries and sprinkle with chopped pistachios.
Cover and chill until firm, about 2–3 hours. (Assumption)
Lift out and slice into pieces with a warm knife.