Drain extra water from the soya nuggets by pressing lightly and put them in a bowl.
Add ginger-garlic, paste, ½ teaspoon chilli powder, salt, 1teaspoon coriander powder, ¼ teaspoon turmeric powder, cumin powder, pepper powder and 1 tablespoon lemon juice, mix well and set aside to marinate for 30minutes.
Heat sufficient oil in a kadai. Deep-fry marinated soya nuggets till golden brown and crisp. Drain on absorbent paper.
Mix together yogurt, remaining chilli powder, remaining turmeric powder, remaining coriander powder, pepper powder, salt and cornflour in a bowl. Add ¼ cup water and mix well.
Heat 2 tablespoons oil in a non-stick pan. Add mustard seeds and let the seeds splutter.
Add red chillies, mix and sauté for 30 seconds.
Add green chillies, ginger, curry leaves and garlic and mix well on high heat. Add chilli paste and mix well.
Reduce heat, add yogurt mixture, mix and cook for 5-10 minutes. Add fried soya nuggets and spring onion greens, reserving some, and toss to mix. Add remaining lemon juice and mix well.
Serve hot garnished with reserved spring onion greens.