Add cut cauliflower, carrots, celery and garlic to a large bowl and mix well. Set aside.
To make the brine, put vinegar, red pepper flakes, mustard seeds, peppercorns, and water in a large pot and bring to a boil. Add the veggies and cook for only 2 minutes, so the veggies keep their crunch. Remove from heat.
Fill quart jars with vegetables, using a slotted spoon to remove veggies from the brine. With the end of a wooden spoon, pack down the veggies. Into each jar, pour 1 cup of the hot brine over the veggies. Then add 3 tablespoons olive oil to each jar. Screw on the lid fairly tightly and turn the jar upside down a couple of times to mix up the brine, olive oil, and veggies.
Losen the lid. Cool completely and then put on lids securely. Refrigerate for 3 hours before enjoying.
Giardiniera will last for two weeks in the fridge.
This simple giardiniera enhances any salad, pizza, bruschetta amd tastes great right out of the jar.
