Growing up, we always made this casserole with cans of Campbell’s mushroom soup, but this made from scratch version is so much tastier! We’ll start with a basic classic bechamel sauce, add a little parmesan, sauteed mushrooms and green beans and bake to perfection. Enjoy!
3 (15oz) pkg. frozen green beans, thawed and blanched and drained
10 TBSP butter
8 oz mushrooms
1 large shallot, diced
4 Cups whole milk
6 Tbsp flour
2 tsp salt
4 oz shredded fresh parmesan cheese
1 8 oz can sliced water chestnuts, drained
1 cup French’s crispy fried onions
Melt 4 TBSP butter in a Dutch oven. Add sliced mushrooms and diced shallot and cook 8-10 minutes until browned and caramelized. Transfer mushroom mixture to a bowl. Add remaining 6 TBSP butter to Dutch oven. Melt butter and whisk in flour, stirring constantly for 1 minute. Warm milk in microwave for 3 minutes on high. Gradually add warm milk to butter and flour, whisking until smooth. Cook while whisking for 4-5 minutes until thick and bubbly. Remove from heat. Whisk in parmesan cheese, salt and pepper to taste and stir until creamy and smooth. Stir drained water chestnuts, mushroom mixture and green beans into the sauce. Top with crispy fried onions. Bake at 350 for 30 minutes. Enjoy!