1. For the fried shallots: Place the oil in a medium saucepan over medium heat. Add sliced shallots immediately and cook, stirring often, until golden brown, 15–20 minutes. Lower heat if browning too fast.

2. Remove shallots with a slotted or fish spatula to a paper towel–lined plate to drain. Season with Creole Cajun seasoning or seasoned salt. Strain oil through a fine sieve and reserve for future use.

3. For the green bean casserole: Preheat oven to 375°F.

4. Bring a large pot of water to a boil. Add green beans and cook 3 minutes. Drain and transfer to an ice bath to stop cooking. Drain again and set aside.

5. Melt butter in a large skillet over medium heat. Add mushrooms and garlic; sauté until tender and lightly golden, 3–4 minutes.

6. Stir in flour until combined. Slowly pour in chicken broth, stirring to remove any lumps and scraping up browned bits.

7. Stir in lemon juice, dijon, worcestershire, thyme, red pepper flakes (if using), nutmeg, salt, and pepper. Simmer 2–3 minutes.

8. Stir in cream and half of the parmesan; cook 1–2 minutes until smooth.

9. Add blanched green beans to a 10×10-inch or 9×13-inch baking dish. Pour mushroom sauce over and toss to coat. Sprinkle with remaining parmesan.

10. Bake 20 minutes. Remove, toss gently, and top with fried shallots. Return to oven 7–10 minutes until shallots are crisp but not burned.

11. Serve immediately.