This slow roasted celeriac proves that sometimes a few ingredients are all you need. With olive oil, salt, and a few hours in the oven, celeriac transforms into a deeply caramelised, tender and rich dish that feels far more complex than the effort involved. It takes a while, but the return on investment is absolutely worth it.

This recipe is inspired by one from Yotam Ottolenghi, but adapted into something a little lighter. It’s served with a sharp dill and Dijon sauce, where the acidity balances the sweetness of the roasted celeriac while the warm spices help draw out its earthy flavour. The whole dish also happens to be vegan, and works just as well served as a main dish as it does served alongside rich dishes like confit duck or braised beef cheeks.
In this Post
- What is celeriac?
- Ingredients
- How to make slow roasted celeriac
- Variations & Substitutes
- Storing & Reheating Leftovers
- Frequently Asked Questions
- The Recipe
What Is Celeriac?
Celeriac, also known as celery root, is a root vegetable believed to have originated in the Mediterranean and Northern Europe. While it’s closely related to celery, it’s cultivated for its large bulbous root rather than its stalks. The stalks and leaves are still edible though, and can be used much like regular celery in stocks, soups and sauces. Celeriac works particularly well roasted, puréed, mashed or added to soups and gratins, but it can also be eaten raw, thinly sliced in a remoulade-style salad.
Ingredients

Celeriac: Despite its rough appearance, celeriac becomes incredibly tender and sweet once slow roasted. For this recipe, there’s no need to peel it, just give it a very thorough scrub and remove the hairy roots.
Olive oil: Since there are so few ingredients in this recipe, a good quality extra virgin olive oil is important. In this recipe it is used in roasting the celeriac, giving it that caramelisation and then also emulsified into the sauce.
Dijon mustard: The dijon mustard will give the sauce a sharpness, while also helping it emulsify.
Fresh dill: Dill brings a freshness to balance the richness and sweetness of the roasted celeriac. The sauce will work with other fresh herbs.
Ground Coriander & Fennel: These warm spices help enhance the earthy flavour of the celeriac. Toast your spices in a dry pan and allow to cool before using.
White Wine Vinegar & Lemon: The acidity is important for balancing the sweetness of the celeriac that develops during roasting. The vinegar provides sharpness, while the lemon keeps the sauce bright and fresh.
How to make slow roasted celeriac

ONE: Pierce the celeriac with a fork all over. Then coat it in the olive oil and salt.

TWO: Bake the celeriac on a parchment lined tray at 190ºC (170ºC fan) for 2.5 hours, basting with the olive oil every 30 minutes.

THREE: The celeriac is done when it is browned all over and you can easily pierce it with a butter knife. Once cooled enough to handle, cut into slices and finish under the grill on high for a few minutes each side.

FOUR: To make the sauce, first bloom the spices in the vinegar for a minute or two.

FIVE: Whisk in the Dijon mustard and lemon juice then slowly add the olive oil while continuing to whisk.

SIX: Lastly fold through the chopped dill with a spatula.
Variations & Substitutions
Swap the herbs. I love the combination of dill and celeriac. But you can use other fresh herbs like chives, tarragon or parsley. (I like to make extra of the sauce to keep on hand for lunches and other dishes)
Try a different sauce. The slow roasted celeriac will pair well with other sauces such as hollandaise or béarnaise. If you are making a main that already has a sauce, you may not need the dill sauce as well.
Storing & Reheating Leftovers
Storing
Leftover slow roasted celeriac can be stored in an airtight container in the fridge for up to 3 days. The dill and Dijon sauce can also be made ahead and stored separately in an airtight container in the fridge. The dill will begin to discolour, but it will still taste good for a few days.
Reheating
To reheat, place the celeriac under the grill in the oven for a few minutes each side to brown, then turn the oven off and leave for a few minutes to continue warming through. Avoid microwaving if possible, as it softens the caramelised exterior.
The sauce is best served at room temperature, so take it out of the fridge 15–20 minutes before serving and give it a quick stir or whisk if it has separated slightly.
Frequently Asked Questions
Yes, the celeriac can be roasted earlier in the day and reheated in the oven before serving. This makes it a great option for dinner parties or entertaining.
Yes, the sauce can be made several hours ahead and stored in the fridge. Just bring it back to room temperature and whisk or stir before serving if it has separated slightly.
Celeriac is a very dense root vegetable, so slow roasting it whole gives it enough time to become completely tender while developing a deeply caramelised exterior.
The Recipe
I’d love to hear how you get on with making this recipe if you try it and how much you enjoyed eating it! Leave a review below for me to read, or tag me on Instagram if you share a photo.
Print
Slow Roasted Celeriac
A simple slow roasted celeriac recipe with deep caramelisation, earthy flavour and a bright dill & Dijon sauce.
- Total Time: 0 hours
- Yield: 4–6 serves 1x
Ingredients
- 1 whole celeriac (approximately 1 kilogram)
- 120 millilitres extra virgin olive oil, divided
- 10 grams kosher salt (or 1% of the weight of the celeriac)
- 25 grams Dijon mustard
- 15 millilitres white wine vinegar
- Juice of half a lemon
- 15 grams fresh dill, finely chopped
- 1/4 teaspoon ground coriander
- 1/8 teaspoon ground fennel
- flaky sea salt, to taste
Instructions
Roast the celeriac
- Preheat the oven to 190ºC (170ºC fan). Line a baking tray with parchment paper.
- Thoroughly scrub the celeriac and trim away any hairy roots from the base. Using a fork, pierce the celeriac all over. Place into a large bowl with half of the olive oil and the kosher salt, then toss well to ensure it is completely coated. Transfer to the prepared baking tray.
- Roast for 2½ hours, basting with the olive oil from the tray every 30 minutes, until the celeriac is deeply browned all over and a butter knife slides in easily to the centre.
- Allow the celeriac to cool slightly until safe to handle, then cut into thick slices. Place under a hot grill for a few minutes on each side until lightly golden and caramelised around the edges.
Make the dill & Dijon sauce
- Lightly toast the ground coriander and fennel in a dry pan over medium heat for 30 seconds until fragrant, then let cool.
- Add spices to a bowl with the white wine vinegar and leave to bloom for 1–2 minutes. Whisk in the Dijon mustard and lemon juice.
- Slowly pour in the remaining olive oil while whisking continuously until emulsified. Fold through the chopped dill and season with flaky sea salt to taste. Spoon over the warm celeriac to serve.
- Prep Time: 15 minutes
- Cook Time: 2.5 hours


Leave a Reply