Melt 1 tbsp of butter in the olive oil over med high heat.Saute mushroom for a minute. Pour in water and scrape out the pan goodness.Add garlic and saute for a minute.Reduce heat to low.Pour in yuzu juice, and add butter.Allow butter to melt and when sauce thickens, remove from heat.Stir in chopped parsley.Serve over pan-seared halibut fillets.