Preheat oven to 450F or 425F convection. Line a baking sheet with parchment.
Add brussels to the baking sheet along with the oil oil and ¼ teaspoon salt. Toss to coat, spread out into an even layer, and bake for 10 minutes, or until nicely charred.
In a small bowl or container, add the cucumbers, vinegar, and remaining ¼ teaspoon salt and toss thoroughly. Set aside. These taste best the longer they sit (overnight is best).
In a high-speed blender, add the nori and blend to grind it up (you can use a tamper tool to help it blend evenly). Add the vinegar, oil, soy sauce, and honey and blend on high until thoroughly combined.
Add warm rice to your bowl and top with the brussels sprouts, carrots, cucumber, and egg. Give the dressing a shake or stir and then drizzle it generously all over. Top with scallions and pickled red onions.