In a 2-cup (500 ml) glass jar, place the cauliflower florets.
In a small saucepan, place the remaining ingredients and bring to boil. Let simmer for 5 minutes. Strain the hot liquid through a sieve and pour into the jar on the cauliflower, up to 1/4-inch (5 mm) from the edge. Close and let cool. Refrigerate. Let rest for 24 hours before serving to allow the flavours to blend.
Pickled cauliflower will keep for at least 3 weeks in the refrigerator.