This Leek and White Bean Casserole is the perfect vegetarian comfort dish that will have you coming back for seconds. It combines creamy, cheesy layers with hearty white beans and leeks, all topped with crunchy paprika-seasoned croutons. The leeks provide incredible flavor and texture, while the white beans make it filling and wholesome. Don’t be intimidated by the ingredient list—most of the items are pantry staples, with just a couple of special additions like leeks and gruyere cheese. The crouton topping elevates this dish with a delightful crunch that contrasts beautifully with the creamy casserole underneath.

Table of Contents

• Ingredients you will need for this Leek and White Bean Casserole
• How to make this Leek and White Bean Casserole with a Crunchy Crouton Top
• Tips and tricks to make the best Leek and White Bean Casserole
• FAQ

Ingredients you will need for this Leek and White Bean Casserole

For the Croutons:

• 5 slices of white bread, diced into cubes
• 2 tablespoons olive oil
• 1 teaspoon paprika
• ½ teaspoon onion powder
• Salt and pepper to taste

For the Casserole:

• 1 tablespoon olive oil
• 1 tablespoon butter
• 1 stalk of celery, diced
• 1 carrot, diced
• 2 leeks, sliced into half moons (white and light green parts only)
• 4 sprigs of fresh thyme
• ½ teaspoon salt
• ½ teaspoon freshly ground black pepper
• ½ cup white wine
• 2 tablespoons flour
• 1 tablespoon Dijon mustard
• 1 ¾ cups chicken stock (or vegetable stock for vegetarian option)
• 2 cans white kidney beans, drained and rinsed
• ⅛ teaspoon freshly grated nutmeg
• 1 cup grated Gruyere cheese

How to make this Leek and White Bean Casserole with a Crunchy Crouton Top

1. Prepare the Croutons:
   • Preheat your oven to 400°F (200°C).
   • Place the cubed bread on a sheet pan and drizzle with olive oil. Sprinkle with paprika, onion powder, salt, and pepper. Toss to combine.
   • Bake for 6-8 minutes, or until golden brown and crispy. Set aside to cool.
2. Cook the Vegetables:
   • In a large pot over medium heat, add the olive oil and butter. Once melted, add the diced celery, carrot, leeks, thyme, salt, and pepper. Cook for 10-12 minutes, stirring occasionally, until the vegetables are soft and translucent.
   • Add the white wine and scrape up any browned bits from the bottom of the pot. Simmer for about 2 minutes, until most of the wine is absorbed.
3. Make the Sauce:
   • Sprinkle the flour over the cooked vegetables and cook for an additional 2 minutes, stirring to coat the veggies evenly.
   • Stir in the Dijon mustard, then slowly pour in the chicken or vegetable stock while stirring continuously. Add the drained white beans and stir in the freshly grated nutmeg.
   • Bring the mixture to a simmer and cook for 3-4 minutes, allowing the sauce to thicken. Remove the thyme sprigs and discard.
4. Assemble the Casserole:
   • Pour the hot bean mixture into a casserole dish. Scatter the grated Gruyere cheese evenly over the top, followed by the crispy croutons.
5. Bake the Casserole:
   • Place the casserole in the preheated oven and bake for 10-12 minutes, or until the cheese is melted and bubbly.
6. Serve:
   • Remove the casserole from the oven and serve immediately.

Tips and tricks to make the best Leek and White Bean Casserole

• Use fresh leeks: Make sure to thoroughly wash the leeks to remove any dirt or sand trapped between the layers.
• Customizable cheese: If you don’t have Gruyere, any melty cheese like cheddar or mozzarella will work well.
• Herb flexibility: While thyme adds great flavor, feel free to experiment with other herbs like rosemary or parsley.

FAQ

Can I make this casserole ahead of time?

Yes, you can prepare the casserole up to the point of baking. Cover and store in the refrigerator for up to 24 hours. Add the croutons just before baking to keep them crispy.

Can I freeze this casserole?

Yes, the casserole can be frozen before adding the cheese and croutons. Thaw in the fridge overnight, then add the cheese and croutons and bake until bubbly.

Can I make this casserole vegan?

To make this dish vegan, use vegetable stock, replace the butter with olive oil, and substitute the Gruyere with a vegan cheese alternative.

What can I serve with this casserole?

This casserole is filling on its own but pairs well with a light green salad or roasted vegetables.

And that’s it for this Leek and White Bean Casserole with a Crunchy Crouton Top! If you make it, please tag me on Pinterest or Instagram so I can see! For more delicious vegetarian recipes, check out my other dishes here. Feel free to leave any questions, comments, or reviews—I’d love to hear from you!

Leek and White Bean Casserole with a Crunchy Crouton Top

Print Recipe

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5 from 3 reviews

• Author: Andrea Buckett

Ingredients

For the croutons 5 slices of white bread, diced into cubes 2 tablespoons of olive oil 1 teaspoon of paprika 1/2 teaspoon onion powder Salt and pepper to taste For the Leek and White Bean Casserole 1 tablespoons of olive oil 1 tablespoons of butter 1 stalk of celery, diced 1 carrot, diced 2 leeks, sliced into half moons (white and light green parts only) 4 sprigs of fresh thyme 1/2 teaspoon salt 1/2 teaspoon freshly ground pepper 1/2 cup white wine 2 tablespoon of flour 1 tablespoon of Dijon mustard 1 3/4 cups chicken stock (or vegetable) 2 cans white kidney beans, drained and rinsed 1/8 teaspoon freshly grated nutmeg 1 cup grated gruyere cheese

Instructions

Preheat oven to 400°F

1. Add the cubes of bread to a sheet pan. Drizzle them with olive oil. Sprinkle the bread with the paprika and onion powder. Season with salt and pepper. Toss to combine. 

2. Cook the bread for 6-8 minutes until golden brown and crisp. Remove from the oven and set aside to cool. 

3. Place a large pot over medium heat and add the olive oil and butter. Add the celery, carrot, leeks, thyme, salt and pepper.  Cook for 10-12 minutes, stirring occasionally so the leeks don’t brown, until the vegetables are soft and translucent. The vegetables will have reduced in volume quite a bit. 

4. Add the wine and scrape any browned bits off the bottom of the pot. Bring to a simmer and cook for 2 minutes until most of the wine has been absorbed. 

5. Sprinkle the flour over the vegetables and cook for an additional 2 minutes, stirring occasionally. Stir in the Dijon mustard. 

6. Pour the chicken stock in slowly while stirring continuously. Add the white beans. Stir in the nutmeg. Bring to a simmer and cook for another 3-4 minutes allowing the sauce to thicken. Remove the thyme and discard.

7. Carefully pour the hot bean mixture into a casserole dish. Scatter the cheese evenly over the top. Add the croutons on top of the cheese.

8. Bake in the preheated oven for 10-12 minutes, until everything is hot and bubbly. 

Serve immediately.