Coat a slow cooker generously with cooking spray or line with a crockpot liner. Add the beans, soup, Worcestershire, cayenne pepper (if using), salt, pepper and cheese. Gently stir ingredients, cover and cook on low heat for 2 hours.
Transfer to a serving dish and spread the onions over the top in a single layer.
Notes
Add 1 teaspoon of garlic or onion powder for an extra punch of flavor.
Feel free to double the recipe! When cooking time is up, divide the mixture between two casserole dishes and top with onions as directed.
To make the recipe even more quickly, cook on high heat for 1 hour.
If fresh green beans are still available in your region, replace the canned beans in the recipe with 2 pounds of fresh, trimmed beans.
If you love the added spice from the cayenne pepper, you may like to sprinkle red pepper flakes over the top before baking, too!