How to Make It
Preheat oven to 250°F. Line a baking sheet with a silicone mat.
Pour about 2 inches of oil into a medium-size high-sided saucepan, and heat over medium to 350°F. Add rice in batches (oil will splatter), and cook until slightly puffed and crisp, about 10 seconds. Using a fine mesh spider, remove rice, and drain on paper towels.
Season puffed rice with a pinch of salt; let cool slightly. Transfer to a medium bowl. Add flax seeds, sesame seeds, simple syrup, hemp seeds, seaweed, and remaining 1 3/4 teaspoons salt. Stir until well combined, and transfer to prepared baking sheet. Spread mixture in a thin, even layer. Bake in preheated oven until crisp, 1 hour to 1 hour and 30 minutes. Let stand until cool enough to handle, and break into pieces.