In a bowl, add boiled potatoes, white peas/matar, onion, green chillies, chaat masala powder, black salt, salt, roasted cumin powder, red chilli powder and coriander leaves. Mix well.
Grind beetroot, ginger, green chillies, coriander leaves, lemon juice, tamarind pulp, sugar, black salt, chaat masala powder, pani puri masala, and red chilli powder to a smooth paste.
Transfer the paste to a bowl. Pour water. Mix well.
Pour it into shot glasses.
Poke a hole in the puri with your thumb, fill it with the potato mixture.
Place it over the shot glass.
Khooni pani puri is ready to serve!