Kale, Walnut, and Cheddar Rosti Tart

I think there is no better definition of what it feels like to bite into this cake than how the author herself defines it: “Sometimes I crave cakes with crunch and texture, like this kale cake topped with rosti and a layer of buttery celeriac gratin. The aromas reveal the sweetness of nutmeg, the smoothness of the garam masala, the fragrance of toasted walnuts, the minerals of kale and the acidity of cider vinegar. If you want to make it a heartier dish, you can accompany it with mashed potatoes.” Anna Jones

Le Creuset Heritage Ceramic Tray 23 cm and Ceramic Plate

Ingredients

For the filling

• A small turnip or rutabaga (about 500 g), peeled and cut into 1 cm pieces
• Olive oil
• Salt and black pepper
• 100 g of walnuts
• 1 red onion, peeled and thinly sliced
• 2 cloves garlic, peeled and thinly sliced
• 2 heaping tbsp flour
• 300 ml of vegetable broth
• 200 g of kale
• 1 tbsp cider vinegar
• 400 g of jugs (1 can, usually)
• 1 heaping tbsp old mustard
• 100g cheddar cheese, crumbled into small pieces

For coverage

• 1 large celeriac, peeled
• ½ nutmeg, whole
• A small bunch of thyme
• 2 tbsp unsalted butter

Elaboration

For the filling

1. Preheat the oven to 200 °C.
2. Spread the chopped kohlrabi on a baking tray, drizzle with olive oil, season with salt and black pepper and roast for about 30 minutes, or until golden and tender.
3. Spread the walnuts on a tray and toast in the oven with the kohlrabi for 6 minutes or until golden. Chop the kohlrabi and set aside.
4. Heat some olive oil in a large frying pan and add the red onion, cook for about 10 minutes or until soft, then add the garlic and cook until starting to brown around the edges.
5. Quickly add the flour and stir for a minute, then add the stock a little at a time, stirring after each ladleful to remove any lumps from the sauce.
6. Remove the kale leaves from the stems, chop the stems very finely and break any large leaves in half.
7. Add the kale to the pan with the vinegar, cover and let the kale simmer for a couple of minutes.
8. Drain the white beans and add them to the tray, using a spoon to mash them slightly.
9. Remove the pan from the heat and add the mustard, cheese, walnuts and roasted rutabaga. Stir, taste and season with salt and pepper, then pour into the Le Creuset Heritage Tray . Continue with topping and baking (steps below).

Covering and baking

1. To make the topping, grate the celeriac using the coarse side of a grater (you can also use a food processor). Place the celeriac in a colander, sprinkle with salt and let sit for a few minutes to remove some of the moisture. You can squeeze the celeriac with your hands to speed up the process a little. Put the celeriac in a bowl and grate the nutmeg over the top. Stir in the thyme leaves.
2. Quickly mix everything together with your hands and then spread it over the pie filling. Add the butter or ghee on top and bake for 20 minutes or until the filling is bubbling and the topping turns golden.