Easy Christmas Casserole Recipe
Add Preferred SourceWhen you’re planning a holiday meal that feels warm, comforting, and perfect for a crowd, this Christmas Casserole hits all the right notes. Packed with creamy, cheesy goodness and fresh leeks, it’s the kind of dish that can quickly become a holiday tradition.
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Whether you’re making it for a family gathering or a festive potluck, this casserole is easy to prepare and makes a cozy addition to any table. I love that it’s simple enough to whip up without adding any stress to my holiday schedule.
Ingredients You’ll Need
You’ll need all the ingredients shown in the photograph below.
How to Make Christmas Casserole with Step-By-Step Instructions
Scroll down for the full recipe card containing a full printable recipe and measurements in both US customary and metric units.
Follow my simple instructions, and you’ll find that making this Christmas Casserole is straightforward and so easy.
Preheat the Oven
Before you start preparing the ingredients, preheat your oven to 350°F (180ºC).
Slice and Soften the Leek
Start by thinly slicing the leek. In a large pot over medium-high heat, melt the butter.
Add the leek and cook, stirring constantly, for about 15 minutes. The leeks should become soft and creamy as they cook down.
SERIOUSLY GOOD
CASSEROLES
37 EASY RECIPES designed for days when you want one dish to do all the work for you. Expect rich, mouthwatering layers that are just begging to be on your dinner table.
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Prepare the Sauce
Mix the cornstarch with ¼ cup of milk until smooth. Add this mixture to the pot along with the remaining milk.
Stir in the gouda cheese, then season with salt and pepper. Keep stirring for about 5 minutes as the mixture thickens and the cheese melts into a creamy sauce.
Assemble the Casserole
Once your mixture is ready, transfer it to a casserole dish. Evenly top it with the shredded parmesan cheese for a golden finish.
Bake and Serve
Bake the casserole in the preheated oven for 15 minutes or until it turns bubbly and the cheese is nicely browned.
Serve it with a sprinkle of fresh parsley for added flavor and color.
Equipment
Ingredients
- 6 leek
- ¼ cup butter
- 4 tablespoons cornstarch
- 1 ½ cup milk
- 1 cup gouda cheese shredded
- Salt and pepper
- 1 ½ cup parmesan cheese
- Fresh parsley to serve
Video
Instructions
- Preheat your oven to 350°F (180°C). Thinly slice the leeks, and in a small bowl, whisk together the cornstarch with ¼ cup of milk until smooth.4 tablespoons cornstarch, 1 ½ cup milk
- In a large pot, melt the butter over medium-high heat. Add the leeks and cook, stirring frequently, for about 15 minutes, until they are soft and creamy.¼ cup butter, 6 leek
- Pour in the cornstarch and milk mixture, then add the remaining milk. Stir in the gouda cheese, season with salt and pepper, and continue cooking for 5 minutes, or until the sauce thickens and the cheese is fully melted.1 cup gouda cheese, Salt and pepper
- Transfer the mixture to a greased casserole dish and sprinkle the parmesan cheese evenly on top. Bake in the preheated oven for about 15 minutes, or until the top is bubbly and golden.1 ½ cup parmesan cheese
- Once baked, remove from the oven and garnish with fresh parsley before serving.Fresh parsley
Notes
- Leek Prep: Leeks often trap dirt between their layers, so slice them lengthwise and rinse them under running water to remove any grit. Pat them dry with a kitchen towel before cooking.
- Thickening the Sauce: To prevent clumping, always mix the cornstarch with a small amount of cold milk before adding it to the hot pot. This slurry will help the sauce thicken evenly without any lumps.
- Cheese Variations: Gouda adds a smooth, mild flavor, but if you prefer a sharper taste, you can swap it with cheddar, or try gruyère for a more nutty flavor. Whichever cheese you choose, make sure it’s a good melting variety to maintain the creamy texture.
- Golden Top: For a crispier top, broil the casserole for the last 2-3 minutes.
- Add Protein: For a more filling meal, stir in cooked, shredded chicken or turkey. This is a great way to use leftovers from other holiday meals while boosting the protein content.
- Make Ahead: To save time on busy days, you can prepare the casserole in advance. Assemble it up to the baking step, cover it, and store it in the fridge for up to 24 hours.
Nutrition
SERIOUSLY GOOD
CASSEROLES
37 EASY RECIPES designed for days when you want one dish to do all the work for you. Expect rich, mouthwatering layers that are just begging to be on your dinner table.
Immediate eBook download. No physical book available.
∙ French Toast Casserole
∙ Crack Chicken Casserole
∙ Four Cheese Ravioli Casserole
∙ Ratatouille Casserole
∙ Sweet Potato Casserole
...and much more!
Includes ad-free recipes like:
Recipe Notes and Expert Tips
I’ve included some helpful tips to ensure your Christmas Casserole turns out perfectly every time.
- Leek Prep: Leeks often trap dirt between their layers, so slice them lengthwise and rinse them under running water to remove any grit. Pat them dry with a kitchen towel before cooking.
- Thickening the Sauce: To prevent clumping, always mix the cornstarch with a small amount of cold milk before adding it to the hot pot. This slurry will help the sauce thicken evenly without any lumps.
- Cheese Variations: Gouda adds a smooth, mild flavor, but if you prefer a sharper taste, you can swap it with cheddar, or try gruyère for a more nutty flavor. Whichever cheese you choose, make sure it’s a good melting variety to maintain the creamy texture.
- Golden Top: For a crispier top, broil the casserole for the last 2-3 minutes.
- Add Protein: For a more filling meal, stir in cooked, shredded chicken or turkey. This is a great way to use leftovers from other holiday meals while boosting the protein content.
- Make Ahead: To save time on busy days, you can prepare the casserole in advance. Assemble it up to the baking step, cover it, and store it in the fridge for up to 24 hours.
How to Store Leftover Christmas Casserole
Leftover Christmas Casserole can be stored in an airtight container in the refrigerator for up to 3 days.
When reheating, use a low to medium heat setting to avoid drying out the casserole or separating the cheese sauce. You can also reheat it in the oven at 300°F (150°C) for 10-15 minutes, covering it with foil to maintain moisture.
Unfortunately, this dish doesn’t freeze well because the dairy-based sauce may separate upon reheating.
Our Top 3 Money-Saving Tips for This Recipe
I’ve added some budget-friendly tips to make this recipe more affordable.
- Buy in Bulk: Purchase leeks and cheese in bulk; they often come cheaper this way.
- Use Off-Brand Cheese: Opt for store-brand gouda and parmesan, which taste just as great.
- Make Your Own Parsley: Grow parsley at home. It’s an easy herb to maintain and saves a bit of money.
What to Serve With Christmas Casserole
Pair your Christmas Casserole with Roasted Turkey, Honey Glazed Carrots, Mac n Cheese, and Roasted Potatoes for the perfect holiday meal.
More Easy Casserole Recipes for You to Try at Home
Here are some more of my casserole recipes that are just as easy and delicious for you to enjoy at home.
Oh THANK YOU! This recipe is just awesome! I grow my own Leeks and can never use up all that I have. I keep them stuck in sand in my basement’s cold cellar, and they last great. However, using them in place of green onions seems like a waste to me, because leeks have such an amazing flavor that they deserve a starring role! This dish does not disappoint at all. My whole family loved it! My oldest daughter has raided my Leeks and made them twice now herself!
You are more than welcome and your leeks must be bursting with flavor being homegrown!