To a medium saucepan, add miniature marshmallows, butter, and brown sugar.

Heat over medium-low heat, stirring occasionally, until melted.

Add a generous amount of green gel food coloring, and stir until color is incorporated.

Add the popcorn to a large baking pan lined with parchment paper.

Drizzle the marshmallow mixture over the popcorn, and toss.

When serving, sprinkle the popcorn with red M&Ms.