Place margarine in 12-ounce casserole.
Microwave uncovered on high (100%) until melted, 25 to 30 seconds.
Stir in honey and nutmeg.
Place banana in honey mixture; roll to coat.
Sprinkle with pecans.
Microwave uncovered until hot, 1 to 2 minutes.
Place rum in 1-cup measure.
Microwave uncovered on high (100%) until warm, about 15 seconds.
Pour rum into metal serving spoon; ignite in spoon and pour over bananas.