Heat the oil in a skillet or large saucepan. When hot, sauté the onion and garlic until the onions turn translucent and begin to brown, about 5 minutes.
Add the broth, and use your spoon to scrape off any bits stuck to the bottom of the pan. Now add all the cocoa, flour, peanut butter, all the spices and whisk well to combine. Bring to a simmer and cook for about 5 minutes until it thickens and is very fragrant.
Use an immersion blender directly in the pot, or add the sauce to a blender, and blend until completely smooth. Boom! A gorgeous flavour packed mole sauce is ready to go. Serve hot. Store leftovers in an air-tight container in the fridge for up to a week.