heat oil in a 12 in skilled over medium heat

add onion,chilli powder, and 1/2 teaspoon salt. cook until onion is soften. about 5 min

stir in garlic and cook for about 30 sec

stir in ketchup,water,brown sugar

simmer until sauce is slightly thicker than ketchup, 8 to 10 min

spoon onto buns