Scrub the potatoes well and parboil them. Heat 3 tbsps oil in a non stick pan and add potatoes. Sprinkle sea salt over them. Add crushed peppercorns to potatoes, mix, cover and cook.
Heat 2 tbsps oil in another non stick pan. Add shallots, cover and cook. Make small slits on cherry tomatoes and add to the onions. Sprinkle sea salt and toss. Cover and cook.
Finely chop fresh basil leaves. Add brown sugar, crushed red chillies, vinegar to onion-tomato mixture and mix. Cover and continue to cook. Add basil leaves, mix and switch off heat.Sprinkle onion seeds and crushed peppercorns on potatoes and toss.
To serve put potatoes in a serving bowl, put onion-tomato mixture over them and serve.