Preheat the oven to 350°. Spread the pecans on a pie plate and toast for 6 minutes, until fragrant. Transfer to a bowl and let cool slightly. Add the cereal and nori and toss well.
In a mini food processor, combine the miso, agave, wasabi and salt. Add the oil and process until smooth. Dollop the mixture over the flakes, pecans and nori and toss with your hands to coat evenly.
Spread the mix on a parchment paper–lined rimmed baking sheet in an even layer. Toast for 18 minutes, stirring and tossing 2 or 3 times, until browned; the mix will crisp as it cools. Transfer to a bowl and serve.