Easy Baked Fish

1 lb fish fillets
1/2 tsp salt
dash of pepper
2 Tbsp margarine or butter melted
1 Tbsp lemon juice
1 tsp finely chopped onion

Heat oven to 400 degrees.  If fish fillets are large, cut into 3 serving pieces.  Arrange fish in un-greased square baking dish 8x8x2 or 9x12x2; sprinkle with salt & pepper.  Mix margarine, lemon juice, & onion; drizzle over fish.  Bake uncovered until fish flakes very easily with fork and is opaque in center; 15-30 minutes.  Sprinkle with paprika if desired.