Saute onion in butter until golden.
Add shrimp and mushrooms; saute and stir until shrimp are pink.
Combine salt, pepper, chili sauce and water; add to shrimp mixture.
Bring to a boil; stir in rice.
Cover; simmer 5 minutes.
Combine sour cream and flour; add to rice mixture.
Heat gently; sprinkle with chives.