Bring 2 cups water to a boil in a medium saucepan. Add kosher salt½ cup, sugar½ cup, juniper berries1 teaspoon, peppercorns½ teaspoon, halved head of garlic1, and 1 thyme2 sprig; stir to dissolve salt and sugar. Transfer to a medium bowl and add 5 cups ice cubes. Stir until brine is cool. Add pork chop1; cover and chill for at least 8 and up to 12 hours.