Chopped one big red onion into thin slices. Add the marinade ingredients listed in Step 1 (salt, turmeric powder, and tamarind concentrate)
Heat oil in a pan, and add all the ingredients listed in Step 2 (except for sugar). Fry for 1-2 mins in medium heat until chili changes color to be dark
Add the marinated onions and stir well. Close lid and cook on low heat for about 5 minutes until onions are browned
Add the sugar, and cook on medium heat for 5-10 mins, until the sugar caramelizes and the onion pieces change their texture and blend together