In a pot over medium heat add the oil. Once the oil is heated and starts to shimmer add the quinoa and cook, stirring constantly, until the quinoa is golden brown and puffed, about 2 minutes. The quinoa will pop similar to popcorn, but it burns easily, so pull it from the heat and place in a cool bowl, even if it is not done popping. Let the puffed quinoa cool to room temperature.
In a medium bowl combine the puffed quinoa, pistachios, pumpkin seeds, puffed brown rice, dried fruit, and cacao nibs. Mix well then reserve ¼ of the mixture in a separate bowl for topping the bark.
Line a large baking sheet with baking parchment.
In a large bowl over a pot of simmering water add the chocolate. Stir until the chocolate is completely melted, about 5 minutes. Remove the bowl from the double boiler and immediately add the larger portion of the nut mixture to the chocolate and fold gently to combine. Spread the chocolate mixture onto the prepared baking sheet until it is about ¼-inch thick. Sprinkle the reserved nut mixture over the top, and sprinkle the sea salt over that, if desired.
Refrigerate the bark for 1 hour then break the part into 1-inch pieces. Store the bark in an airtight container in the refrigerator.