- Preheat the oven to 400°F.
- Pour the bag of Mrs. Cubbison’s Parmesan Crisps into a food processor and chop until the crisps become smaller crumbs. Measure 2 tablespoons of crumbs for the onion breading and reserve the rest to top the green bean casserole.
- Place a large pot of water over high heat and bring to a boil. While the water is coming to a boil, fill a large bowl with ice water. Once the water is boiling, add the green beans and cook just until tender, about 6 minutes. Drain and place the green beans in the ice water until they are chilled. Drain thoroughly and set aside.
- Place 3/4 cup of the flour in a wide, shallow pan along with the 2 tablespoons of Parmesan Crisp crumbs, garlic powder, salt, and pepper, then stir together to combine. Place the beaten eggs in another shallow pan seasoned with salt and pepper.
- Dip the sliced Peri & Sons Sweetie Sweet onions into the flour mixture, then into the egg, and then the flour again. Place on a plate and repeat with the remaining onions.
- Fill a large, deep skillet with 2 inches of vegetable oil and bring to 350°F. Fry the onions, taking care not to overcrowd the pan, then transfer to a paper towel lined plate. Season with salt.
- Place a medium saucepan over medium heat. Add the Challenge Butter followed by the remaining diced onions, mushrooms, salt, and pepper. Cook until tender, about 4 minutes, then stir in the remaining 1/4 cup of flour and garlic. Cook for 2 minutes more. Stir in the chicken broth, adding a little at a time, and then the half and half. Season with salt and pepper.
- Place the cooked green beans in a 1.75 qt casserole dish and ladle on the mushroom mixture. Top with the remaining Parmesan Crisp crumbs and the fried onions. Bake in the oven for 15 minutes, then serve.