Drain and rinse the soaked chickpeas thoroughly under cold running water.
Place the chickpeas in a large heavy-bottomed pot and cover with 1.5 liters of fresh water.
Bring to a boil over high heat, then use a slotted spoon to skim and discard any foam that rises to the surface.
Add the diced onion, bay leaf, and 40ml of the extra virgin olive oil to the pot.
Reduce the heat to low, cover with a tight-fitting lid, and simmer for 75 to 90 minutes, or until the chickpeas are completely tender and starting to break down.
Stir in the remaining 40ml of olive oil, the lemon juice, dried oregano, salt, and pepper.
Continue to simmer uncovered for another 10 minutes, stirring occasionally to help the starch from the chickpeas emulsify with the oil and lemon into a creamy broth.
Remove the bay leaf and serve hot.