In a small dish, combine dill, garlic powder and sea salt. Set aside.
In a separate dish, whisk together the olive oil, pickle juice and dijon mustard.
Place the popcorn in a large mixing bowl. Drizzle half of the olive oil mixture over the popcorn, then toss to distribute. Drizzle the remaining olive oil mixture and toss again. Sprinkle the popcorn with half of the dill mix at a time, tossing to distribute in between. Taste and adjust salt as needed. Transfer to a serving bowl and serve immediately.