Cook rice in boiling salted water according to package instructions. Add the peas 5 minutes before the end of cooking time, cook until done. Drain, rinse with cold water, drain and let cool. Quarter the peppers, clean, wash and cut into fine strips.
Drain the mushrooms, let them drip off and, depending on their size, possibly halve them. Clean and wash spring onions and cut into fine rings. Mix sour cream, milk, vinegar, sugar and curry. Season to taste with salt and pepper.
Mix all salad ingredients and season the salad once again.