Preheat your oven to 350F degrees.

Place the green bean casserole on a baking sheet and cover it with foil. You can also use a baking dish, casserole dish, or a dutch oven.

Bake for 20-25 minutes, or until heated through.

Remove the foil during the last few minutes of baking if you want the topping to be extra crispy.

Place the green bean casserole in a microwave-safe bowl or dish. Or add to a small bowl for small portions.

Cover and heat for two to three minutes, depending on how much you heat up. You can start with medium power and medium heat and adjust if needed.

Stir once halfway through.

When removing, be careful of excess steam.

Add to a medium-sized pot, pan, or skillet and place on the stove.

Turn to medium-low heat and occasionally stir until the casserole is heated through.

You may need to add liquid such as chicken broth or butter for the best texture.

Add the leftover green bean casserole to your slow cooker.

Set the temperature to low and heat for two to three hours.

Stir occasionally and serve when fully heated through.

Preheat your air fryer to 375F degrees.

Place the green bean casserole in a heat-safe dish that does not touch the heating element.

Place the dish in the air fryer basket and cook for six to eight minutes, stirring halfway through.