Line a baking sheet with parchment paper. Set aside.
Chop the dark chocolate into small pieces.
Melt the chocolate using a double boiler or microwave in short bursts. Stir often until smooth.
Pour the melted chocolate onto the parchment paper.
Spread it into an even layer, about 1/4 inch thick.
Sprinkle dried cranberries evenly over the chocolate.
Add the chopped nuts on top. Press them gently so they stick.
Sprinkle flaky sea salt over everything.
Let the bark set at room temperature or place it in the fridge for 20 minutes.
Once firm, break into pieces and serve.