These pickled onions will be perfect on your favourite burger, on a charcuterie board, with your favourite cheese, with your Sunday roast... delicious!
Makes approximately four 500ml jars
2 cups/480 ml apple cider vinegar
¾ cup/150 g granulated sugar
2 tbsp pickling salt
3 lbs/1.4 kg red onions, trimmed and thinly sliced
2 tsp mustard seed
1 tsp celery seed
½ tsp red pepper flakes
Combine the vinegar, 1½ cups/360 ml water, sugar, and salt in a pot over high heat and bring the brine to a boil. Add sliced onions to brine and stir to combine. Reduce heat to medium and simmer briefly to soften onions.
Meanwhile, combine the remaining spices in a small bowl and stir to blend. Add the spice blend to the sterilized jars, distributing evenly.
Using tongs, evenly divide the onions between the 4 jars. Pour hot brine into each jar, leaving ½ inch/12 mm headspace. Gently tap the jars on a towel-lined countertop to help loosen any bubbles before using a wooden chopstick to dislodge any remaining bubbles. Check the headspace again and add more brine if necessary.
Wipe the rims, apply the lids and rings, and process in a steam canner for 10 minutes. Let these pickles cure for at least 48 hours before eating.