1-Rinse and trim 1 pound of fresh: Rinse and trim 1 pound of fresh green beans to remove any woody ends.
2-In a medium saucepan, mix 1 cup: In a medium saucepan, mix 1 cup of water, 1 cup of white vinegar, ¼ cup of sugar, and 1 tablespoon of salt over medium heat. Stir until sugar and salt dissolve.
3-Add 2 smashed garlic cloves, 1 teaspoon: Add 2 smashed garlic cloves, 1 teaspoon of red pepper flakes, and 1 teaspoon of mustard seeds while the brine heats.
4-Bring the mixture to a gentle simmer: Bring the mixture to a gentle simmer for about 2-3 minutes.
5-Place the trimmed green beans in a: Place the trimmed green beans in a clean jar, packing them tightly but gently. Pour the hot brine over the beans until fully submerged.
6-Let the jar cool to room temperature: Let the jar cool to room temperature before sealing it tightly with a lid.
7-Store the jar in the refrigerator for: Store the jar in the refrigerator for at least 24 hours before enjoying.