Spray the slow cooker with the non-stick cooking spray if desired.
Add the drained green beans to your slow cooker.
In a medium-size bowl, whisk the cream of mushrooms soup, milk, black pepper, and onion powder until smooth.
Pour the soup mixture over the beans. Add half (one canister) of the french friend onions. Stir gently.
Place the lid and cook on HIGH for 2½ hours.
Brown the remaining canister of French fried onions in a skillet on the stove top. Set the skillet to medium high heat, stir the onions around until brown (about 3 minutes).
Sprinkle the onions over and serve. (If you are traveling, you can brown your onions at home then add them to the slow cooker right before serving).
Video
Notes
Can I use fresh (trimmed and cut) or frozen green beans?
Use 10 cups fresh (trimmed and cut) or frozen green beans instead of canned.
Cook for 3.5 hours on high or until the green beans are tender.
How long can I keep this on the warm setting after cooking?You can keep this on the warm setting for 3 hours. Though keep an eye on it and make sure the edges aren't scorching, stir or turn off if the edges are getting too hot.Can I brown the onion on top of the casserole at the end of the cooking time (instead of using a skillet to brown them.)?If your slow cooker is oven safe (check your manual), sprinkle the remaining canister of French fried onions to the top of the casserole.
Remove the slow cooker insert from the heating element and place it in the oven WITHOUT the lid.
Cook for 10 minutes at 350°F or until the onions are browned.
OR place the onions in a small dish in the oven for 10 minutes or until browned, then sprinkle over the casserole.
Can I halve this recipe?Yes, you can cut this recipe in half. You will only need to cook for 2 hours on high before adding the remaining onions.