In a 1 quart microwave safe casserole combine apple juice, brown sugar, margarine, and nutmeg.
Micro cook, uncovered, on 100% power (high) for 1 minute.
Add bananas, tossing to coat.
Cook on 100% power (high) for 1 1/2 to 2 minutes or till bananas are heated through; spoon sauce over bananas once.
Pour rum over bananas in casserole.
Carefully ignite with a long match.