Add the split peas to a large pot over medium-high heat.
Add enough water to cover the peas by 2 cm (0.8 inches).Bring to a boil and, once boiling, reduce the heat to low-medium and cook for20 minutes or until soft.
Some foam might naturally form on top of the cooking liquid– in that case, just take it out with a slotted spoon.
Drain the peas once they are cooked and cooled. Add them to the bowl of a food processor along with the sea salt, black pepper, za’atar, garlic clove, olive oil, lemon juice and water.
Run the machine until you get a very smooth hummus.
If the mixture seems too dry, add 1 or 2 additional tablespoons of water.
Put the split pea hummus in a medium sized deep plate.
Add the red onion and capers on top and finish with a generous drizzle of olive oil.