Preheat and prep: Heat the oven to 375°F (190°C). Grease a 9x13-inch casserole dish or similar baking dish.

Blanch the green beans: Bring a large pot of salted water to a boil. Add green beans and cook 3–4 minutes until bright green and just tender. Drain and shock in ice water, then drain well. Dry thoroughly so the sauce won’t get watery.

Cook the onions: In a large skillet, heat 1 tablespoon butter and 1 tablespoon oil over medium heat. Add the sliced onion with a pinch of salt. Cook 8–10 minutes, stirring occasionally, until golden and lightly caramelized. Transfer half to a bowl to use in the topping.

Sauté the mushrooms and garlic: To the onion remaining in the skillet, add another tablespoon of butter and the mushrooms. Cook 5–6 minutes until mushrooms release moisture and brown slightly. Stir in the garlic and cook 30 seconds until fragrant.

Make the cream sauce: Lower heat to medium-low. Add heavy cream and almond milk (or broth). Whisk in cream cheese until smooth. Stir in 1/4 cup Parmesan, a pinch of nutmeg, salt, pepper, and optional paprika or cayenne. Simmer 2–3 minutes, stirring, until slightly thickened. Taste and adjust seasoning.

Combine with green beans: Add the drained green beans to the skillet and toss to coat evenly with sauce. If your skillet isn’t oven-safe or is too full, transfer everything to the prepared baking dish.

Mix the topping: In a small bowl, combine almond flour, remaining 1/4 cup Parmesan, reserved caramelized onions, crushed pork rinds (if using), a tablespoon of chopped herbs, a pinch of salt, and the remaining 1 tablespoon butter (melted). Stir until crumbly.

Assemble: Sprinkle the topping evenly over the green beans and sauce.

Bake: Place in the oven for 18–22 minutes, until the topping is golden and the sauce is bubbling around the edges.

Rest and serve: Let the casserole sit for 5 minutes before serving so the sauce sets slightly. Garnish with extra herbs if you like.