Drain the beans & slip them out of their skins. Set the skinned beans in a pot with the onion & just enough water to cover. Turn the heat to medium, bring to a boil, add salt & reduce to a simmer. Cover & cook until the water has almost evaporated & the beans are tender & pulpy, 20 to 25 minutes.
Drain the beans. Mix together the lemon juice, olive oil, parsley, salt & pepper. Toss with the garlic & the cooked beans.
Serve as part of an antipasto plate or as we would serve a potato salad.