Makes 1 quart
½ small head cauliflower, cut into bite-size florets
1 small red onion, sliced ¼ inch thick
1 clove garlic, thinly sliced
¾ cup red wine vinegar
¾ cup distilled white vinegar
2 tablespoons sugar
Kosher salt
1 teaspoon coriander seeds
1 wide strip lemon zest
Bring a medium pot of water to a boil. Add the cauliflower and cook until crisp-tender, about 2 minutes. Drain and rinse under cold water until cool. Pack the cauliflower, onion and garlic into a 1-quart jar.
Make the brine: Combine the red wine vinegar, distilled white vinegar, ¾ cup water, the sugar, 1½ teaspoons salt, the coriander seeds and lemon zest in a small saucepan and bring to a boil.
Pour the hot brine into the jar and let cool completely. Cover and refrigerate overnight or up to 1 week.