Butter a shallow, heat-resistant, non-metallic baking dish lightly.
Place stuffed sole fillets in baking dish.
Sprinkle with salt and pepper to taste.
Sprinkle onions over fish fillets and pour wine over fish.
Heat, covered with clear plastic wrap, on full power 7 to 8 minutes or until fish flakes easily with a fork.
Baste fish with wine and onions several times during cooking.
Set poached fish aside.
In a medium-sized, heat-resistant, non-metallic bowl melt the 1/3 cup butter or margarine on full power 45 seconds.
Add mushroom slices and heat, uncovered, on full power 2 minutes.
Blend in flour until smooth.
Gradually add cream, stirring until smooth.
Return sauce to microwave oven and heat on ROAST, uncovered, 6 to 7 minutes or until mixture is thickened and smooth.
Stir occasionally.
Add 1/2 cup fish liquid from baking dish to mushroom sauce and stir until well blended.
Place fish fillets on a heat-resistant, non-metallic serving platter.
Spoon mushroom sauce over fish.
Heat, uncovered, on roast for 3 to 4 minutes or until heated through.
Sprinkle with paprika