Green Bean Casserole From Scratch: My Spectacular Take!

Ingredients

• 2 large yellow onions, thinly sliced (approximately 4 cups)
• 2 cups all-purpose flour
• 1 teaspoon salt
• 1/2 teaspoon black pepper
• 1 quart vegetable oil, for frying
• 2 pounds fresh green beans, trimmed and halved
• 4 tablespoons unsalted butter
• 1 pound cremini mushrooms, sliced
• 1 medium yellow onion, finely chopped
• 2 cloves garlic, minced
• 1/4 cup all-purpose flour
• 3 cups chicken broth (low sodium)
• 1 cup heavy cream
• 1/4 cup dry sherry (optional)
• 1/4 teaspoon grated nutmeg