Chef Tom shows you how to make the perfect green bean casserole by using the Napoleon P500 Gas Grill! Enjoy the scratch-made cream of mushroom base, fresh green beans, and fried buttermilk onion straws. Plus, learn a great technique to use your gas grill as a broiler.
WHAT YOU'LL LOVE
- The gas grill doubles as a broiler with one simple setup. Positioning a cast iron griddle on the shelf above the casserole and running the rear burner on high creates focused top-down heat, browning the surface without needing a separate broiler.
- A scratch-made cream of mushroom base skips the canned soup entirely. Building the sauce from fresh mushrooms, onions, wine, and half and half gives it real depth that canned soup can't match, while still delivering that familiar comforting texture.
- Buttermilk-brined onions fry up extra flavorful. Soaking the sliced onions in a buttermilk-and-brine mixture before dredging adds a tangy depth to the fried topping that a plain buttermilk soak wouldn't achieve.
- Blanching the green beans first keeps them from turning mushy. Par-cooking them separately before folding into the sauce ensures they hold their texture through the final bake instead of overcooking.
Homemade Green Bean Casserole
Tom Jackson
Rated 5.0 stars by 5 users
Category
Side Dish
Cuisine
American
Servings
12
Prep Time
20 minutes
Cook Time
51 minutes
Calories
300
Chef Tom fires up the Napoleon P500 Gas Grill for Homemade Green Bean Casserole! Check out the scratch-made cream of mushroom base, fresh green beans and fried buttermilk onion straws on top, as well as a killer technique that turns your gas grill into a broiler!
Ingredients
- 2 lb fresh green beans, trimmed 1” lengths
- 4 oz bacon, diced
- 6 tbsp unsalted butter
- 1 lb assorted mushrooms (baby bella, oyster, shiitake, crimini), small dice
- 1 large yellow onion, small dice
-
2 tbsp Cattleman’s Grill Trail Dust All-Purpose Seasoning
- 1/2 cup dry white wine
- 2 tbsp garlic, minced
- 1/2 cup flour
- 3 cups half and half
- 1/2 cup Parmigiano Reggiano, grated
- 2 cups buttermilk
-
2 tbsp Cattleman’s Grill Butcher House Brine
- 2 cups yellow onion, thin sliced
- 2 cups flour
- vegetable oil, for frying
-
Jacobsen Salt Co. Kosher Sea Salt, as needed
For the topping:
Directions
- Start by prepping the onion topping. Combine the buttermilk and Cattleman’s Grill Butcher House Brine in a quart container. Whisk well to combine. Add your thin liked onions to the container and submerge them in the buttermilk. Let soak until you’re ready to bread and fry the onions.
- Preheat your Napoleon Prestige P500RSIB Gas Grill. Turn the outside burners to high. Turn the rear/rotisserie and inside/middle burners on low. Place a Napoleon Reversible Cast Iron Griddle in the center of the second shelf. This will act as a broiler to brown the top of the casserole.
- Bring a medium sized pot of water to a boil on the infrared side burner. Blanch the green beans in the gently simmering water until tender, but not mushy, about 7 minutes. Remove with a slotted spoon and set aside.
- Preheat a Lodge & Quart Dutch Oven inside grill while the green beans are being par-cooked.
- Transfer the dutch oven to side burner. Add the diced bacon and cook until crispy. Remove the bacon from the dutch oven and place on paper towels.
- Add the butter and melt. Add the mushrooms and onions. Season with Cattleman’s Grill Trail Dust All-Purpose Seasoning, Cook, stirring occasionally until most of the water has cooked out of the onions and mushrooms and they are starting to stick to the bottom, about 10 minutes.
- Deglaze the cast iron with the white wine. Reduce until there is not visible liquid left in the bottom. Add the garlic and flour. Cook, stirring for one minute. Add the half and half and bring to simmer. Add parmesan and stir to melt. Turn off the heat. Add the green beans. Mix well.
- Transfer the mixture to a Lodge Cast Iron Casserole Pan. Smooth out the top. Transfer to the grill, underneath the griddle. Cook for about 20 minutes.
- Meanwhile, fry the onions on the side burner. Rinse out the dutch oven used to make the cream of mushroom. Wipe dry with towels and place on the side burner of the grill. Add vegetable oil for frying, about 1” deep. Preheat to about 400ºF.
- Remove the onions from the buttermilk, a handful at a time. Dredge in the flour in a shallow pan. Transfer to a wire rack over a sheet pan. After all onions are breaded, begin frying.
- Fry in 3-4 batches, cooking the onions just until golden brown, about one minute, then remove and transfer back to the wire rack.
- Top the casserole with the fried onions and continue cooking another, 10 minutes, or until the casserole is bubbling and the top is browned. If the top begins to get too brown, turn off the rear infrared burner that is heating the griddle.
Recipe Note
Recipe FAQ
Why position a cast iron griddle above the casserole on the grill?
This setup turns the grill's rear burner into an effective broiler, directing focused heat downward to brown the top of the casserole without needing separate broiler equipment.
Why make the cream of mushroom base from scratch instead of using canned soup?
Building it with fresh mushrooms, onions, white wine, and half and half develops real depth of flavor that canned soup can't replicate, while still landing on that same familiar, comforting texture.
Why brine the onions in a buttermilk-and-brine mixture before frying?
The added brine gives the onions a tangy depth beyond what a plain buttermilk soak provides, which comes through in the fried topping's flavor.
Why blanch the green beans before adding them to the sauce?
Par-cooking them separately first ensures they hold their texture through the final bake, rather than turning mushy from being cooked twice.
Can I make this without a broiler-capable gas grill setup?
Yes — a standard oven works well: bake the assembled casserole at 375°F until bubbling, then switch to the broiler setting for the final few minutes to brown the fried onion topping.
How indoor-friendly is this recipe?
5 out of 5 — every step here, including the browning technique, translates directly to a stovetop and oven with no loss of quality.
Recipe Highlights
Grill-as-broiler setup: Positioning cast iron above the casserole with the rear burner on high creates focused top-down heat for browning.
A scratch-made mushroom base: Building the sauce from fresh ingredients rather than canned soup adds real depth of flavor.
Buttermilk-and-brine soak for the onions: This extra step gives the fried topping more flavor than a plain buttermilk dredge would.
Blanching the green beans first: Par-cooking them separately protects their texture through the final bake.
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Nutrition
Nutrition
- Nutrition Serving Size
- 10.29 oz
- per serving
- Calories
- 300
- Carbs
- 25 grams
- Protein
- 9 grams
- Fat
- 18 grams
- Sodium
- 155 milligrams
