Take baby potatoes in a cooker, add salt and cover with water. Pressure cook for 3 whistle, simmer and cook for 5 mins.
Turn off the heat and let the pressure go all by itself. Open the cooker, drain it and cool this down. Now peel off the skin and set aside.
Take dry red chillies, cut them open, remove the membrane and seeds. Soak this in hot water for 10 mins.
Drain it and add it to a blender along with tomato. Make it into a fine puree. Set aside.
Heat oil in a kadai. Add in ginger, garlic and onions. Saute for a min.
Add in chilli tomato paste and cook till oil separates.
Now add in ketchup, soy sauce, salt, sugar and vinegar. Mix well.
Add in water and bring it to a boil. Add in cooked potatoes and simmer the pot covered for 10 mins.
The gravy will be thick and the potatoes will absorb the curry.
Add spring onion and mix well.
Serve with pulav, fried rice, naan or anything.