In a medium bowl combine the chopped olives, celery, onions (if using) and garlic.
In a small container whisk together the olive oil and lemon juice - pour over the olive mixture and toss to coat. Season to taste with salt and pepper.
Refrigerate for 4 hours or overnight before serving.
Notes
Storage: Keep refrigerated for up to 5 days in an airtight container.Serving ideas:
Quick salad topping lettuce or spinach.
Spooning inside a traditional muffuletta-type sandwich or a pita bread sandwich.
Top a bowl of cottage cheese.
Top a bowl of whipped feta for a dip.
Top a layer of hummus and serve with pita bread as a dip.