Heat oil in a pressure cooker. Add onion, ginger garlic paste, and turmeric. Fry for a few minutes. Add capsicum and green or red chillis. Fry for a minute more. Add the tomato, washed dal, salt, and water.
Cook on high pressure for 2 whistles. Simmer on low for ten minutes.
Remove the pressure cooker lid. Check for salt and spice. Add red chilli powder, coriander powder, and sugar. If the dal is too thick, add water to get the consistency you want. Garnish with chopped coriander leaves. Serve hot.