Rough chop the mango flesh, ginger and chili pepper. Place them in a saucepan over medium-high heat, along with minced garlic, and the remaining ingredients except for the olive oil, and bring to a simmer.
Lower and cook with a lid on for 15 minutes.
Remove from the heat, lid off and cool for 5 minutes.
Transfer to a blender or food processor and puree to a smoother texture. Add the olive oil and pulse just a few times to mix.
The finished sauce is now ready to use, or can be stored in an air-tight jar in the fridge for up to a week.