Place a pan on medium heat and add in your veggie oil.
Add in your mustard seeds, turmeric, chopped garlic, and sliced onion. Stir and fry for 3 minutes.
Next, spoon in your cinnamon, cayenne, curry powder, salt, and sugar. Once again, give it a stir and fry for a further 3 minutes.
Gently pour in your coconut milk and sprinkle in your red chillies and chilli flakes. Leave to simmer for 5 minutes.
Transfer your mango wedges into the curry, place the lid on your pan, and leave to simmer on low-medium heat for 15 minutes.
Once your mango is soft, serve up with your cooked rice, a sprinkle of coriander and chilli.