Make Ahead Updated Green Bean Casserole with Onion Rings (Side Dish)

2 lbs. green beans trimmed, 1/2 large onion, diced,  2 tbsp. olive oil.

2 strips bacon cooked.  (I actually used that already made bacon and put into the white sauce once it was done.)

Cream Sauce 

1/4 cup butter, 1/4 cup flour, 2 cups milk, 1 tsp. salt, 1/4 tsp. pepper, 1 cup panko, 1/4 cup powdered Parmesan cheese, 1 package frozen onion rings or freshly made homemade onion rings.

In a large pot of boiling salted water (1 tsp. salt), add green beans and cook for about 10 minutes, drain and blot out any excess water.

In a separate pot, over medium heat, add olive oil and onions.  Cook until just translucent.  Keeping onions in pot, add butter and once melted, add flour and whisk until all the flour is absorbed, turn down heat and add milk, whisking vigorously so no lumps form.  Once all smooth all the heat to thicken up your cream sauce.  Add salt and pepper.

Special note - with respect to your white sauce, a tad thicker white sauce is better because it will keep super well in the freezer.  Think of a thicker pancake batter.  You can always add a couple more tablespoons of flour if you need.

Put green beans into a Pam sprayed casserole dish and pour the onions and cream sauce over.  Top and sprinkle with panko and Parmesan cheese. 

To Freeze

Cool down and wrap in both Saran Wrap and Aluminum Foil.  

Pop into the freezer for up to two weeks, but no longer.

Defrosting and Reheating

When you want to get the casserole ready for your dinner, take the casserole out to defrost first - will take about 1 hour depending on how big your casserole is.  Once it has defrosted,  pop into a 350 degree oven.  There will be a little liquid in the bottom of the casserole, but if you cook for up to 1 1/2 hours, it will evaporate and a delicious little crust will form on the bottom too.  At same time you are warming up and cooking green bean casserole, pop in your frozen, preferably panko onion rings and cook those until done.

Once the green bean casserole is warmed through, cooked and browned, top with onion rings or top with canned French Fried onions 15 minutes before casserole is done.  Enjoy!