String bean casserole (also known as green bean casserole) is a comforting, creamy baked dish made with tender beans, a rich mushroom sauce, and a crispy onion topping. Originally popularized in the 1950s, it has become a classic side dish loved for its creamy texture and savory flavor.
This version is inspired by a fresh, homemade approach using real ingredients instead of canned soup for a richer and more flavorful result.
🍽️ Ingredients
Main Ingredients:
- 1½ pounds fresh green beans (trimmed & halved)
- 2 tablespoons olive oil
- 16 oz cremini mushrooms (sliced)
- 4 garlic cloves (minced)
- 2 tablespoons fresh thyme
- 2 tablespoons tamari or soy sauce
- ¼ cup all-purpose flour
- 3 cups milk
- 1½ teaspoons Dijon mustard
- ½ cup grated Parmesan cheese
- ¼ teaspoon black pepper
- 1½ cups crispy fried onions
👉 These ingredients create a creamy mushroom sauce and crispy topping, which are key elements of a traditional casserole.
Also Read: Chicken & Rice Casserole
👩🍳 Step-by-Step How to Make
Step 1: Prepare the Beans
- Bring a pot of salted water to boil.
- Add green beans and cook for 3–4 minutes (blanching).
- Transfer immediately to ice water to keep them crisp and green.
Step 2: Cook the Mushroom Sauce
- Heat olive oil in a pan over medium heat.
- Add mushrooms and cook until soft (8–10 minutes).
- Stir in garlic, thyme, and tamari.
- Sprinkle flour and mix well.
Step 3: Make It Creamy
- Slowly add milk while stirring continuously.
- Add Dijon mustard and simmer until thick (15–20 minutes).
- Mix in Parmesan cheese and black pepper.
Step 4: Assemble the Casserole
- Preheat oven to 200°C (400°F).
- Spread some sauce in a baking dish.
- Add green beans, then pour remaining sauce on top.
Step 5: Add Topping & Bake
- Sprinkle crispy fried onions evenly.
- Bake covered for 10 minutes, then uncovered for another 10 minutes until golden.
Step 6: Serve
- Garnish with extra Parmesan if desired.
- Serve hot and creamy.
🥗 Nutritional Information (Per Serving – Approx.)
| Nutrient | Amount |
|---|---|
| Calories | 220–260 kcal |
| Protein | 8–10 g |
| Carbohydrates | 18–22 g |
| Fat | 12–15 g |
| Fiber | 3–4 g |
| Calcium | 15–20% DV |
Values may vary depending on ingredients and portion size.
Also Read: Street Corn Chicken Casserole
💡 Tips for Best Results
Homemade sauce gives a fresher, less processed taste compared to canned versions.
Don’t overcook beans, they should stay slightly crisp.
Use fresh mushrooms for deeper flavor.
Add toppings near the end to keep them crispy.
