Half fill a cooking pot with water and add the chickpeas. Bring to a boil over high heat.
Cook for about 5 minutes and then drain chickpeas in a strainer.
Heat a splash of olive oil in your pressure cooker or in cooking pot over high heat.
Add the onion and garlic and saute until softened.
Add chickpeas along with 2 liters of water. Pressure cook on high for 20 minutes or reduce heat to medium and cook for 2-3 hours on the stovetop (depending on how soft you want your chickpeas).
Add the olive oil and season with salt and pepper. Make sure there's enough water to slightly cover the chickpeas. Otherwise, add a bit more.
Simmer over medium heat uncovered, stirring occasionally until soup thickens. Takes about 30 minutes.
Add the lemon juice and oregano, and serve.