Clean and prep your string beans and heat up a cast iron skillet on the stove.
Dice your mushrooms and yellow onions and set aside. Place 8 pieces of bacon on your heated skillet and cook until crispy. Cut up the bacon into small pieces.
Add the mushrooms and diced yellow onions to the skillet you cooked the bacon in and mix until soft. Add the bacon back in. Follow this up with your flour, seasoning, and heavy cream.
Add the string beans and mix them all together. The string beans need to be covered in the flour mix that's on the stove. Add the crispy onions on top.
Bake the casserole at 350 degrees for 40-45 minutes until the green beans are soft. If you need more time in the oven, leave it in for an hour.
Keyword dinner recipes, holiday recipes, quick recipes, side dish