Description
This Green Bean and Potato Casserole is a comforting and creamy side dish perfect for holiday meals or weeknight dinners. Featuring tender baby potatoes and fresh green beans enveloped in a rich cheese sauce with a crispy fried onion topping, it combines simple ingredients for a deliciously satisfying bake.
Ingredients
Scale
Vegetables
- 1 ½ pounds baby potatoes, halved
- 1 pound fresh green beans, trimmed
- 1 medium onion, thinly sliced
- 3 cloves garlic, minced
Sauce
- 2 tablespoons olive oil
- 3 tablespoons butter
- 3 tablespoons all-purpose flour
- 2 cups whole milk
- 1 cup chicken or vegetable broth
- 1 teaspoon Dijon mustard
- 1 teaspoon salt
- ½ teaspoon black pepper
- ½ teaspoon smoked paprika
Cheeses & Toppings
- 1 cup shredded cheddar cheese
- ½ cup grated Parmesan cheese
- 1 cup crispy fried onions (for topping)
Instructions
- Prepare Oven and Baking Dish: Preheat your oven to 375°F (190°C) and grease a 9×13-inch baking dish to prevent sticking.
- Cook Potatoes and Green Beans: Bring a large pot of salted water to a boil. Add the halved baby potatoes and cook for 8–10 minutes until they are just tender. In the last 3 minutes of cooking, add the trimmed green beans to soften slightly. Drain both and set aside.
- Sauté Aromatics: In a large skillet, heat the olive oil over medium heat. Add the thinly sliced onion and sauté for 5–6 minutes until soft and translucent. Add the minced garlic and cook for an additional 30 seconds until fragrant.
- Make the Cheese Sauce: Push the onion and garlic to one side of the skillet. Add the butter to the cleared area and allow it to melt. Stir in the flour and cook, whisking, for 1 minute to form a roux. Gradually whisk in the whole milk and broth, stirring continuously to avoid lumps.
- Season and Thicken Sauce: Add Dijon mustard, salt, black pepper, and smoked paprika. Continue to simmer the sauce for 3–4 minutes until it thickens and coats the back of a spoon.
- Add Cheeses: Remove the skillet from heat and stir in the shredded cheddar and grated Parmesan cheese until melted and smooth.
- Combine Vegetables and Sauce: Add the cooked baby potatoes and green beans into the skillet and gently toss to coat them evenly with the cheese sauce.
- Assemble Casserole: Transfer the mixture into the prepared baking dish, spreading it evenly. Sprinkle the crispy fried onions evenly over the top to create a crunchy topping.
- Bake: Place the casserole in the preheated oven and bake uncovered for 20–25 minutes until bubbling and golden brown on top.
- Serve: Remove from oven and let it cool slightly before serving warm as a hearty side dish or vegetarian main if vegetable broth is used.
Notes
- This casserole can be prepared a day ahead and refrigerated; just bake before serving.
- For extra richness and flavor, sprinkle crumbled bacon over the top before baking if not strictly vegetarian.
- Ideal as a festive holiday side or a comforting weeknight dinner accompaniment.
- Prep Time: 20 minutes
- Cook Time: 40 minutes
- Category: Side Dish
- Method: Baking
- Cuisine: American
Nutrition
- Serving Size: 1 cup
- Calories: 280
- Sugar: 5g
- Sodium: 480mg
- Fat: 15g
- Saturated Fat: 7g
- Unsaturated Fat: 7g
- Trans Fat: 0g
- Carbohydrates: 27g
- Fiber: 4g
- Protein: 9g
- Cholesterol: 30mg
