Cauliflower Leek Gratin
SHARE THIS RECIPE!
If you need a last-minute vegetarian side dish for Thanksgiving or Christmas, this is the ticket! This Cauliflower Leek Gratin with crispy fried onions is hearty, creamy, crispy, and delicious! It has the decadence of mac and cheese without all the heaviness of a mac and cheese. The cauliflower keeps it nice and light!
Have extra cauliflower and leeks after making this? Try my Cream of Potato and Leek soup, I add a little cauliflower to the soup to make it extra creamy!
Ingredients:
- Cauliflower I prefer to buy the cauliflower whole (as opposed to pre-cut in bags). I find it’s fresher that way. Avoid any cauliflower that has brown spots on it which means it’s getting old.
- Leeks: If you have the option, buy prewashed without the tops. This saves on refrigerator and trash space.
- Unsalted Butter and All-Purpose Flour to create the base of the sauce
- Whole Milk This will give you a thicker, creamier sauce
- Ground nutmeg Just a few pinches to create a nutty flavor to the sauce
- Minced Garlic always buy fresh and mince yourself. It will taste way better than way.
- Grated Gruyere Cheese for both the sauce and the topping
- Fresh thyme adds a beautiful fall flavor to the creamy cheese sauce.
- Crispy Fried Onions French’s or any kind you use for a Fresh Green Bean Casserole. Do not skip the onions! They are the best part!
Make-Ahead Tips
The best way to pre-make this recipe is to prepare all the components a day ahead, then assemble them together the day of, bake, and serve!
Step#1: Roast the Cauliflower
- Cut the cauliflower into half florets, lengthwise.
- Toss in olive oil and seasoning.
- Roast until the cauliflower is fork-tender.
- Allow them to cool if you are making this a day ahead, then cover and refrigerate.
Step#2: Saute the Leeks
- Cut the leeks into thin matchsticks.
- Saute them in olive oil, in batches. This will allow them to become wilted and browned.
- Allow them to cool, cover, and refrigerate if you are making this a day ahead.
Step#3: Make the Sauce
- Melt the butter in a large saute pan until foamy. Add the flour, create a paste and cook for one minute.
- Then add the milk, and boil until it thickens, and coats the back of a spoon.
- Add the garlic, nutmeg and thyme, along with salt and pepper to taste.
- If making this a day ahead, allow to cool and then cover and refrigerate.
To Assemble:
- Place the cauliflower in a 2-inch deep, 9 x 14 gratin pan.
- Distribute the cauliflower on top, making sure that each scoop contains a little bit of the leeks!
- If you made the sauce the day before, reheat it on the stovetop, pour it over the vegetables, top it with cheese and onions, and bake.
Cauliflower Leek Gratin
This Cauliflower Leek Gratin with crispy fried onions is hearty, creamy, crispy, and delicious! It has the decadence of mac and cheese without all the heaviness of a mac and cheese. The cauliflower keeps it nice and light!
Ingredients
- 4 Tbsp (60 ml) olive oil, separated
- 3.25 pounds (1475 grams) of cauliflower cut into florets
- 2 leeks, white parts only, sliced into 3-inch long matchsticks
- 2 Tbsp (28 g) unsalted butter
- 2 Tablespoons (18 g) all-purpose flour
- 2 cups (480 ml) whole milk
- Kosher salt and freshly cracked pepper, to taste
- 1 garlic clove, minced
- 2 tsp (10 ml) fresh thyme
- ⅛ tsp (a large pinch) nutmeg
- ⅓ cup (35 g) gruyere cheese
TOPPING:
- ⅔ cup (70 g) Gruyere Cheese
- ⅓ cup (25 g) French’s fried onions
- 1 Tbsp (15 ml) Freshly chopped parsley (optional)
Instructions
- Preheat oven 425F (220C).
- Cut each cauliflower floret in half lengthwise to create a flat side. Transfer to a large bowl and toss with two tablespoons (30 ml) of olive oil, season with salt and pepper to taste. Spread them out on a sheet pan in an even layer and roast for 20-30 minutes until fork tender. Set aside to cool.
- In a large non-stick saute pan, add the remaining olive oil. Saute the leeks in two batches (so they are not crowded) and continue to cook until wilted and slightly browned. Season with salt and pepper to taste.
- Transfer the cooked cauliflower to a 9 x 14 (23 x 33cm) oval gratin pan, distribute the leeks on top, being sure to cover the cauliflower evenly, and set aside.
- Then, melt the butter on medium heat in the cleaned-out saute pan. Once foamy, add the flour and whisk together until a paste forms, then continue to cook and whisk for one minute. Then slowly add the milk and whisk together, increasing the heat to high until the mixture starts to bubble and thicken enough to coat the back of a spoon, about 3-4 minutes. Then reduce the heat to medium. Add the garlic, nutmeg, and thyme and season to taste with salt and pepper. Then whisk in the ⅓ cup (35 g) of cheese.
Pour the sauce evenly over the cauliflower leek mixture. Add the remaining cheese and top with the onions. - Place in a preheated 400F (200F) oven for 15-20 minutes or until the cheese has melted and the onions are glistening. Top with freshly chopped parsley if desired, and serve immediately.
Notes
Make Ahead Notes:
Day Before:
Roast the cauliflower and cook the leeks. Cover and refrigerate. Then make the sauce, keep in a separate container, cover and refrigerate.
Day Off:
Preheat the oven to 400F (200C). Place the vegetables in the gratin pan. Meanwhile, heat the sauce in a sauce pan, thin with a little milk if needed. Once hot, pour over the vegetables, cheese, and onions, and bake as directed above.
Nutrition Information:
Yield: 6 Serving Size: 1Amount Per Serving: Calories: 417Total Fat: 18gSaturated Fat: 5gTrans Fat: 0gUnsaturated Fat: 12gCholesterol: 21mgSodium: 208mgCarbohydrates: 53gFiber: 9gSugar: 12gProtein: 14g
