Heat a pan with cooking oil. To the hot oil add some cumin seeds, chopped green chillies, onion slices and par boiled sliced potatoes. When the potatoes are cooked well, add sliced tomato and sliced green, red and yellow bell peppers. Mix well. Add crushed coriander seeds, salt and all ground spice. Mix again. Toss and cook the vegetables for some time. Transfer it to a serving dish. Garnish it with chopped coriander.