- 1 cup red-wine vinegar
- 3 cups white-wine vinegar
- 1 cup sugar
- 1/2 cup salt
- 1 tablespoon black peppercorns
- 1 tablespoon brown mustard seeds
- 5 or 6 red pearl onions
- 2 to 3 heads cauliflower
Place cauliflower in a large glass heatproof jar or canister, positioning florets against the glass; set aside.
Fill a large pot with 8 cups water. Add both vinegars, sugar, salt, peppercorns, mustard seeds, and onions. Bring to a boil.
Carefully pour boiling liquid over cauliflower; let cool to room temperature. Cover and transfer to refrigerator. Let chill overnight or up to 1 week.