📖 Instructions

1. **Blanch the Green Beans (The Key to Crispness!):** First things first, get a large pot of salted water boiling like crazy. While that’s heating up, trim the ends off your fresh green beans. Once the water is at a rolling boil, carefully drop the beans in. Let them cook for just 3-4 minutes. You’re looking for vibrant green and tender-crisp – not soft or mushy, okay? Immediately drain the beans and plunge them into an ice bath (a bowl of ice water) to stop the cooking process. This step is super important to keep them bright and with a little bite. Drain well and set aside.
2. **Fry the Shallots (Crispy Gold!):** Grab your large oven-safe skillet. Heat about 1/2 cup of vegetable oil over medium heat. When it shimmers, add your thinly sliced shallots. Stir them around frequently to ensure even browning. You want them to turn a beautiful golden brown and get wonderfully crispy. This usually takes about 5-8 minutes. Keep a close eye on them, as they can burn quickly! Once they’re golden, use a slotted spoon to transfer them to a plate lined with paper towels to drain. Sprinkle a tiny pinch of salt over them while they’re hot. Reserve 2 tablespoons of the shallot oil in the skillet, draining any excess.
3. **Build the Mushroom Sauce (From Scratch Goodness!):** Place the skillet with the reserved shallot oil back over medium heat. Add the sliced cremini mushrooms and cook, stirring occasionally, until they’ve released their liquid and are nicely browned, about 5-7 minutes. Sprinkle in the minced garlic and cook for another minute until fragrant. Now, sprinkle the flour over the mushrooms and stir constantly for 1-2 minutes; this cooks out the raw flour taste. Slowly pour in the chicken or vegetable broth, whisking continuously to prevent lumps. The mixture will start to thicken. Next, pour in the heavy cream and milk, whisking until smooth and creamy. Bring it to a gentle simmer, then reduce the heat to low. Stir in the soy sauce (it adds depth!), Dijon mustard (a little tang!), and a generous pinch of nutmeg. Season with salt and freshly ground black pepper to taste. Let it gently bubble for 3-5 minutes, allowing the sauce to thicken slightly. Taste and adjust seasonings if needed; it should be rich and savory.
4. **Assemble the Casserole (Almost There!):** Gently fold the blanched green beans into the creamy mushroom sauce in the skillet. Make sure they're all coated beautifully. Take about half of your crispy fried shallots and gently stir them into the green bean mixture, too. This adds a lovely texture throughout, not just on top.
5. **Bake It Up (Golden Perfection!):** Preheat your oven to 375°F (190°C). If your skillet is oven-safe, great! If not, transfer the mixture to a 9x13-inch baking dish. Sprinkle the remaining fried shallots evenly over the top of the casserole. Pop it into the preheated oven and bake for 20-25 minutes, or until the casserole is bubbling around the edges and the topping is beautifully golden brown and extra crispy.
6. **The Herb Finish (The Grand Finale!):** Once baked, carefully remove the skillet from the oven. Let it rest for 5 minutes. Then, sprinkle generously with fresh chopped parsley and thyme. The warmth of the casserole will bring out their amazing aroma. Serve hot and watch it disappear!