My husband is Calabrian. He's a self-proclaimed "proud wog" (hold fire dahlinks, they're his words not mine and he uses the with great pride!). He grew up in a family that made their own olives, pickles, pasta, tomato passata and wine. And every so often he comes home with a box of olives he acquired from the farmers market....

This is his recipe.

Ingredients

Black olives (freshly picked)
Salt
Chilli, finely sliced
Fennel seeds
6-8 cloves garlic, sliced
Filtered water

Method

First soak your olives to remove the bitter tannins:

Slice a cut or two in each olive (this helps the bitter tannins to release!)
Place in a bowl, bucket, jar or fermenting crock* and cover with water. My fermenting crock comes with a weight to place over the olives to keep them submerged. If you don't have a weight, use a plate to keep the olives submerged. 
The soaking water will discolour and get a scum on it - that is the bitter tannins releasing!
Pour off the water once or twice a day every day for about 2 weeks until the water is clear.

When the soaking water is clear you are ready to brine your olives!

Place your olives in a jar or fermenting crock* with chilli, garlic, fennel seeds and 2 tablespoons salt.
Cover with water and make sure they are fully submerged (see above).
Seal jar and leave in a cool place.
Every 5 days for the first 15 days, pour off water and add a new brine (salty water) mixture to your jar/crock. 
Then keep in a cool place for a further 1-2 months. Check the taste at this point and if necessary leave for another 1-2 months. Let your taste buds guide you!
Once they are brined to your preferred taste, store in the fridge and enjoy!

NOTE: These are traditional home-brined olives. They won't taste like the vinegary store-bought olives.