This celeriac gratin is the result of an experiment one cold winter day last year. It was so delicious that the dish never actually made it to the dining table; after baking it we just stood in the kitchen, eating it off the top of the oven like savages!
Now a firm favourite in my repertoire, I make this side dish at most family gatherings. And sadly, there are never any leftovers!
- 1 large head of celeriac (about 950g)
- 1 lemon (juice only)
- 500 ml milk
- 50 g plain flour
- 50 g unsalted butter
- 200 g grated cheese
- 1 tsp english mustard
- 150 ml double cream
- 1 onion (sliced)
- 2 garlic cloves (minced)
- 75 g panko breadcrumbs
- 25 g parmesan cheese
- Preheat the oven to 200c / 180C fan.
- Cut the celeriac in half, then into 3-5mm slices. Chop each slice into thick strips, then toss the celeriac with the lemon juice to prevent browning.
- Heat up the milk, either on the stove or in a microwave, until it is steaming hot.
- Add the butter to a saucepan, and melt over a medium heat. Sprinkle the flour on top, and combine together with a wooden spoon. Stir the mixture continuously for a couple of minutes to cook out the flour.
- Add a splash of the hot milk, and stir to create a smooth paste. Add another splash of milk and repeat, until all of the milk has been used up. You can add larger splashes of milk as the sauce starts to become thinner, but you must add the milk in stages to prevent the formation of lumps.
- Cook the sauce for about 5 minutes, stirring it all the time.
- Take the saucepan off the heat (to prevent graininess) and add the grated gruyère. Stir together immediately to ensure that the cheese melts.
- Add the mustard and cream to the sauce, then season with salt and pepper to taste.
- Place a shallow casserole dish over a medium heat. Add the oil and butter to the pan, and when hot, add in the minced garlic and sliced onions. You want to soften the onions rather than fry them, so make sure that the heat does not get too high. This should take about 5 minutes.
- Once the onions are softened, remove from the heat, and add the celeriac and the sauce to the shallow casserole. Gently toss everything together, and then smooth over the surface.
- Sprinkle the panko breadcrumbs over the whole surface of the gratin in an even layer, then add the grated pamesan, and a good shaving of nutmeg, before finally seasoning with salt and pepper.
- Bake for about 45 minutesm, until the top is pleasingly browned.
- Remove from the oven and leave to stand for 5-10 minutes. For a final flourish, sprinkle over some finely chopped chives.