Wash and chop the bell pepper into chunks. Heat a nonstick pan with 1 tsp oil. Add the peppers and sauté on high flame. Add the chopped garlic, curry leaves also to the pan and sauté well.
Remove and add chopped tomatoes, salt, red chili powder, and turmeric. Then, add coriander leaves. Cover with a lid so that the tomatoes get soft faster.
Once the tomatoes are cooked well, remove and allow to cool.
Then take everything in a mixer, add tamarind extract and blend to a smooth paste. Add water if required.
Heat another pan with oil, add mustard, urad dal, and curry leaves. When the mustard splutters, add it to the chutney.