Celery Root Gratin

Rich, savory, and slightly sweet, this plant-based casserole has significantly less calories than it’s non-vegan counterparts! 208 calories per serving.

Print Recipe Pin Recipe

Servings 6

Ingredients

¼ cup vegetable broth or water plus more as needed
2 medium yellow onions chopped
¼ cup flour any kind
1 medium celery root about 1 ½ pounds
Optional: chopped broccoli florets and stems

FOR THE BECHAMEL:

6 cups unsweetened non dairy milk homemade works best
2.5 TBS tapioca starch
1 TBS olive oil
1 clove garlic
2 tsp salt
1 kalamata olive *see note below
¼ tsp Black pepper
1 pinch cayenne

FOR THE TOPPING:

2 TBS olive oil
1 cup panko
1 pinch salt

Instructions

Pre-heat the oven to 375.
Heat ¼ cup vegetable broth or water in a large pot over medium heat. When hot, add the onions and saute for 10 minutes. Add more liquid as necessary to prevent sticking/burning.
While the onions are cooking, place all of the bechamel ingredients in a blender and blend until smooth. After the onions have cooked for 10 minutes, stir in the flour, evenly coating the onions. Slowly stir in the blender contents, scraping up the bottom to avoid clumps of flour. Once fully combined, allow the sauce to simmer for 3 - 5 minutes, stirring frequently.
Peel the celery root. Cut the root into quarters, and thinly slice each quarter. I highly recommend using a mandolin with the 2.5 mm setting. Set aside.
To make the panko topping, heat 2 TBS olive oil in a medium skillet over medium-high heat. Add the salt and panko. Stir frequently until lightly toasted. Keep a close eye or it will burn!
Assemble the casserole: Grease an 8x11 or 9x13 casserole dish (8x11 will produce a creamier casserole). Start with a layer of celery root slices. Overlap the slices slightly, leaving no gaps. If using broccoli, sprinkle a layer over the celery root slices. Spread a layer of sauce over the vegetables. Repeat this process until all sauce and celery root have been used, ending with sauce. Top with the panko topping.
Cover with foil and cook for 50 minutes, until the celery root is soft enough to be pierced with a paring knife. If your casserole is piling above the rim of the dish, make a tent with the foil to prevent it from sticking to the panko topping. Remove the foil after 50 minutes and heat under the broiler for a few minutes, just until the crumbs begin to brown. Remove from oven. This casserole serves best if it’s allowed to cool for at least 15 - 20 minutes so the sauce thickens and the servings hold their shape.

Notes

Celery root (also known as celeriac) is the highly flavorful root of a plant similar to the celery plants we eat. It tastes quite a bit like celery, and is starchy and bulbous like a potato or turnip. In this recipe, we’re using it much like you would potatoes in a potato gratin or scalloped potatoes. If you can’t find celery root, you may use potato.

I like to use a kalamata olive in the bechamel sauce to give it a salty tangy flavor. Feel free to use anything similar - capers, pimentos, any kind of olive, or lemon juice.