Ingredients
Vegetables
- 1 lb (450 g) fresh green beans, trimmed and cut into 1-inch pieces (or 2 cans of green beans, drained)
- 8 oz (225 g) fresh mushrooms, sliced
- 1 medium onion, thinly sliced
- 2 cloves garlic, minced
Sauce
- 2 tablespoons olive oil or butter
- 2 tablespoons all-purpose flour
- 1 cup vegetable or chicken broth
- ½ cup milk (or non-dairy milk)
- 1 teaspoon soy sauce
- Salt and pepper, to taste
Topping
- Frozen shoestring fries (quantity as needed to cover casserole)
Instructions
- Preheat oven: Set your oven to 450°F (232°C) to prepare for baking the shoestring fries.
- Bake fries: Arrange frozen shoestring fries in a single layer on a baking sheet and bake for 15 minutes until starting to crisp.
- Sauté onions: In a large skillet, heat olive oil or butter over medium heat. Add the thinly sliced onions and cook, stirring occasionally, for about 10 minutes until caramelized and golden brown.
- Add mushrooms and garlic: Add the sliced mushrooms and minced garlic to the caramelized onions. Continue cooking for 5-7 minutes until the mushrooms are tender and any released liquid has evaporated.
- Incorporate soy sauce: Pour the soy sauce over the mushroom mixture and stir to combine evenly, enhancing the umami flavor.
- Make roux: Sprinkle the flour over the mushroom mixture and stir well. Cook this for 1-2 minutes to eliminate the raw flour taste and help thicken the sauce.
- Add broth and thicken: Gradually pour in the vegetable or chicken broth while stirring constantly. Continue stirring until the mixture thickens into a creamy sauce.
- Add milk and season: Stir in the milk, then season with salt and pepper to taste. Mix everything well to create a smooth, flavorful sauce.
- Combine green beans: Add the trimmed green beans to the skillet with the mushroom sauce. Stir thoroughly to coat the beans in the sauce.
- Preheat oven again: Lower the oven temperature to 350°F (175°C) for baking the casserole.
- Prepare casserole dish: Grease a 9 x 13-inch baking dish. Pour the green bean and mushroom mixture evenly into the dish.
- Bake casserole: Bake in the preheated 350°F oven for 20 minutes to heat through and meld flavors.
- Add fries topping: Remove the casserole from the oven and evenly spread the baked shoestring fries over the top.
- Final bake: Return the casserole to the oven and bake for an additional 10-15 minutes until the fries are golden, crispy, and the casserole is thoroughly heated.
Notes
- For a creamier texture, use whole milk or a creamy non-dairy milk alternative.
- Fresh green beans provide the best texture, but canned green beans can be used as a shortcut. Drain well before using.
- If you prefer a less salty dish, reduce or omit the soy sauce, or use a low-sodium version.
- The frozen fries topping adds great texture, but you can substitute with fried onions or crushed crispy onions for a traditional twist.
- Make sure to caramelize the onions properly to deepen the flavor of the mushroom sauce.
- Prep Time: 15 minutes
- Cook Time: 45 minutes
- Category: Side Dish
- Method: Baking
- Cuisine: American
- Diet: Vegetarian