Super-quick sweet and sour giardiniera

An excellent starter with cured meats or a side dish: crisp, tempting and sweet and sour, and very quick to make. I sterilised the jars before filling because I eat it soon. For long storage, the original method calls for a second sterilisation by boiling the jars, immersed and covered in water, for 15/20 minutes. Thanks to my sister-in-law for this recipe! I recommend making only a few jars at a time and eating them, as it is quick to prepare.
INGREDIENTS FOR 4 JARS OF 5OO G
1600 g mixed vegetables: red and yellow peppers, cauliflower, carrots, small onions, courgettes, celery and green beans
1 glass white vinegar
3 and a half glasses olive oil (I used my Garda extra virgin olive oil)
1 tablespoon salt
1 tablespoon sugar
I choose the vegetables I want to use.
I clean and wash them thoroughly.
I cut all the vegetables into fairly large pieces. Choose your favourites, weighing them to reach the required amount.
I pour a full glass of vinegar into a large pan.
I add 3.5 full glasses of oil.
1 heaped tablespoon sugar.
1 heaped tablespoon salt.
I stir, add the vegetables and put on the heat.
As soon as it boils, I count 3 minutes and turn off the heat. It seems short, but do not cook longer: the vegetables must remain firm.
I let it cool completely, spoon the giardiniera into the previously sterilised jars and distribute the cooking liquid too.
I put the lids on and invert the jars to create a vacuum.
After 5 minutes, I turn them upright. They are ready when you hear the usual vacuum click. Without a second sterilisation, do not keep them for a very long time.