In 10 second increments melt the chocolate in a bowl in the microwave, stirring after each time until smooth.
Line a baking sheet with parchment paper. Pour 1/3 of the melted dark chocolate onto the parchment paper and use a spatula to spread into an even layer, 1/8" thick.
Evenly sprinkle the chocolate with half the pretzels, cherries, coconut, and pistachios.
Pour the remaining melted dark chocolate and spread to evenly cover ingredients.
Evenly sprinkle with remaining pretzels, cherries, coconut, and pistachios. Garnish with flaky sea salt.
Place in the refrigerator to let the bark cool until set, then break into pieces and serve.