Peel and thinly slice the onions.
Coat the bottom of a large frying pan on medium heat with the olive oil. Once hot add the onions and season with salt. Let the onions cook for approximately 30 to 45 minutes, stirring every 5 minutes or so to ensure they don't burn.
In a bowl, mix the tahini, lemon juice,garlic and water together until it becomes smooth and creamy
Pour the liquid into the pan with the onions and stir until well combined. Stir in the chill powder. Cook on medium heat for approximately 5 minutes until it begins to bubble.
Serve topped with fresh parsley