One of Italy's best-loved culinary specialities, Tropea onions can be prepared in sweet and sour sauce to provide a tasty side dish that will add a touch of verve and colour to any menu.

One of Italy's best-loved culinary specialities, Tropea onions can be prepared in sweet and sour sauce to provide a tasty side dish that will add a touch of verve and colour to any menu. Here's how to prepare them easily and safely in our Lock-Eat jars.

Jars needed: Lock-Eat Food Jar

Ingredients:
1 kg Tropea red onions
2 cups white vinegar
2 cups water
1/3 cup white sugar
2 tablespoons sea salt
1 teaspoon pink peppercorns

Preparation:
Peel, wash and thinly slice the onions, divide them into two or more Lock-Eat jars, also of different sizes, previously sanitised, and add the pink peppercorns.

Pour the vinegar, water, sugar and salt into a saucepan and bring to a boil. Stir until the sugar and salt have dissolved, about 1 minute. Allow to cool slightly and pour over the onions up to 2 cm from the rim of the previously boiled Lock-Eat jars to sanitise them. Close the jar, taking care to clean the edges.

Place the jars in the pot with the lids facing upwards. To prevent the jars from bumping into each other and splitting during cooking, place a tea towel in the bottom of the pot and wrap each jar with additional tea towels. Cover the jars with warm water and bring to a boil.

Once it comes to a boil, close the pot with the lid and cook for 30 minutes over a low flame. The jars should always remain covered with water, so add hot water if necessary to restore the initial level.

At the end of the process, let the jars cool down in the same boiling water. Then remove the jars by gripping them by the glass, using gloves and pot holders.

The onions will be ready once they turn bright pink.

If you wish, you can already taste them after a few hours. After 4-5 days of resting, they become perfect.

Keep the onions cool in the pantry, or directly in the fridge.

They have no preservation problems: the sweet and sour onions retain their characteristics for a long time even once the jar has been opened. Of course, they should be stored in the refrigerator after the first consumption.