Cook oil in a small saucepan over low heat 3 minutes.
Add popcorn kernels, rosemary sprigs, and 1 teaspoon sea salt. Remove mixture from heat; cover and let stand at room temperature 48 hours.
Drain kernels, reserving 3 tablespoons oil; discard rosemary sprigs.
Place 3 tablespoons reserved olive oil and popcorn kernels in a large Dutch oven.
Cook kernels, covered, over high heat, shaking pan often for 4 minutes until popping begins to slow down. Remove popcorn from heat, and let stand 2 minutes or until popping stops.
Place popcorn in a large bowl.
Add remaining 1/2 teaspoon salt, pine nuts, and chopped rosemary, and toss. Serve immediately.