1. Prep all of your ingredients and measure out your spices. Heat the oil over medium-high heat in a large pot. Saut the ginger, garlic, and red chilli for a minute. Add the spices all at once and sauté for another minute. Note: Be sure to have all your ingredients measured ahead of time, as you will need to work quickly as soon as your spices go in the pot to prevent them from burning.
2. Add the diced mangoes along with the salt, sugar, and vinegar, stirring to combine. Bring the mixture to a rapid boil, then reduce heat to medium-low. Simmer for about 1 hour, or until the mixture reduces significantly and begins to thicken.
3. Once cooked, remove the chutney from heat and allow it to cool in the pot. Once cooled, pour into resealable glass jars and store in the fridge for up to 2 months, or even longer in the freezer.