How to Make It
Heat the oil large pot over medium heat. After the oil is hot, add the popcorn kernels and the 1-tablespoon of rosemary, and then shake the pot to gently toss the kernels until they are all coated with oil. Cover with a splatter screen or a lid that is placed slightly ajar to allow the steam to escape.
Cook until the popcorn popping frequency slows to several seconds between pops. Remove from heat, allow a minute or two for any final pops, and then pour into a large bowl.
In a small saucepan combine the butter and remaining 1/2 teaspoon of rosemary. Melt the butter over medium heat.
Drizzle over the popcorn and season with salt and pepper, tossing occasionally as you butter, salt, and pepper the popcorn.