The spice mixture can be made in advance; store it in an airtight container in a cool, dark place up to six months.
- 1/8 teaspoon crushed red-pepper flakes
- 1/2 teaspoon cumin seeds
- 1/2 teaspoon coriander seeds
- 3/4 teaspoon garlic powder
- 1/4 teaspoon freshly ground pepper
- 1/4 teaspoon dry mustard
- 1 tablespoon vegetable oil
- 1/2 cup popcorn kernels
- 1/4 cup fresh lime juice
- 6 tablespoons unsalted butter
- coarse salt
Place pepper flakes, cumin, and coriander in a spice grinder; grind until fine. Transfer to a small bowl, and stir in garlic powder, pepper, and mustard until combined. Set aside.
Heat a 4-quart pot over medium-high heat, and add oil. When oil is hot, pour in popcorn kernels. Cover, and keep pan over heat until first kernel pops. Shake pan gently, close to burner; continue shaking until kernels stop popping, 4 to 5 minutes.
Bring lime juice to a boil in a small skillet over medium heat. Reduce heat; cook until liquid is reduced to 1/2 tablespoon. Add butter, and swirl to melt; add spice mixture. Drizzle over popcorn while stirring to coat evenly. Season with salt, and toss. This popcorn is best eaten the day it is prepared.