Sweet Potato, Spinach and Goats' Cheese Tart - Recipe by Gareth Whitton and Catherine Way.
Ingredients
1 × baked shortcrust pastry shell (page 23)
Caramelised onions:
150 g caster (superfine) sugar
5 g salt
140 g sherry vinegar
500 g onions, finely sliced
Leek and sweet potato cake batter:
350 g sweet potato
200 g leek, sliced into 2 mm (1/16 in) rounds
65 g natural almond meal
15 g plain (all-purpose) flour
2.5 g baking powder
3 g salt
105 g egg
75 g brown butter (page 111)
Olive oil
Salt, to season
Dukkah crumbs:
45 g Panko breadcrumbs
20 g chopped roasted almonds
40 g dukkah
1 g salt
Vegetable oil, for toasting
Spinach and shallot puree:
100 g shallots, sliced thinly
80 g vegetable oil
130 g spinach leaves
100 g pouring (whipping) cream
Goats' cheese custard:
140 g goats' cheese
130 g spinach and shallot puree, see above
150 g pouring (whipping) cream
4 g salt
100 g egg yolk
Method
Preheat the oven to 165 C.
Caramelised onions:
Place a frying pan over low heat and add a small amount of the sugar. Allow this to melt and slowly caramelise, repeat the process with the remainder. Stir with a wooden spoon until the caramel is an even golden brown. At this point, add the salt and vinegar, and bring to a boil over medium–high heat.
Allow this mixture to reduce until the bubbles are thick, then add the onions. Stir with a wooden spoon until the onions start to break down. Continue to simmer this mixture, while stirring, until the liquid is almost gone and the onions are soft. Drain off any excess liquid then cool in the fridge.
Leek and sweet potato cake batter:
Peel and cut the sweet potato into batons approx. 2 cm thick and 7 cm long. Toss the sweet potato in a little olive oil and salt, then roast on a tray lined with baking paper for 20 minutes, or until soft. Once cooked, remove from the oven and allow to cool in the fridge until you are ready to assemble the tart.
Place a large pot of water on the stove and bring to a boil. Season the water with a good amount of salt – approximately 15 g per litre of water.
Blanch the leek in the salted boiling water for 15 seconds, then drain and refresh in iced water. Squeeze out the water from the leeks – you should have approximately 130 g of leek left.
To make the batter, first weigh out the dry ingredients in a bowl and stir them together. Add the eggs to a mixing bowl and, using a stand mixer fitted with a whisk attachment, mix until combined on low speed (or do so by hand).
Melt the brown butter in a saucepan. You want this to be warm enough so that the liquid doesn’t cool down too quickly, but cool enough so that it doesn’t develop any burnt characteristics. If the butter is too hot, it can also fry the egg mixture as you add it, so a thermometer is useful (we aim for roughly 100 C.
Once the butter comes up to temperature, slowly pour it into the whisked eggs while mixing (or add little by little if whisking by hand). Ensure that the mixture is well emulsified, as this will ensure that the butter doesn’t bleed out later, giving the cake a greasy texture. Then add in the dry ingredients and mix until well combined, ensuring that there are no lumps suspended throughout the batter. Vigorously mix the leek into the cake batter by hand to ensure it has been fully distributed.
To assemble and bake:
Spread the cake batter into the pastry shell. Take the roasted sweet potato pieces and place into the cake batter in three concentric circles. Use a palette knife to smooth out the cake so that the sweet potato pieces are flush with the level of the cake.
Bake the tart for approximately 18 minutes, or until the crust is an even golden brown and the centre of the tart is firm. Remove from the oven and allow to cool inside the tin. Using the back of a spoon, press down firmly on any areas where the cake has risen unevenly so that the surface is flat.
Spread 150 g of caramelised onions on top of the cake layer and set aside.
Dukkah crumbs:
Heat a small amount of vegetable oil in a small pan and add the Panko breadcrumbs. Stir gently to ensure they cook evenly and drain through a sieve once they start to turn a light golden brown – they will continue to colour, so be sure not to take it too far. Mix the fried breadcrumbs with the chopped almonds, dukkah and salt.
Spinach and shallot puree:
Add the shallots to a frying pan and cover with the vegetable oil. Bring to a simmer over medium heat, then lower the heat so that the onions can confit gently until they are slightly golden brown in colour. Turn off the heat and allow the shallots to cool in the pan. Bring a large pot of salted water to the boil and blanch the spinach for 1 minute.
Drain the spinach and refresh in iced water to keep the colour vibrant. Once refreshed, squeeze out the water from the spinach and add to a saucepan along with the drained shallots. Stir to combine over medium–high heat. Once cooled slightly, add to a blender and blend for 2 minutes, or until smooth. Reserve the puree in the fridge until needed.
Goats' cheese custard:
Bring the cheese, spinach and shallot puree, cream and salt to a simmer in a saucepan. Meanwhile, add the egg yolks to a tall measuring jug. Once the mixture has come to a simmer, pour it into the jug with the eggs and using a hand-held blender, blitz the custard until it is smooth and glossy. Pour this mixture over the jam layer in the pastry shell and bake the tart for 15 minutes, or until the custard is set.
To finish:
Allow to cool at room temperature, then remove from the tart from the tin and portion into slices with a hot, sharp knife. Dust each slice with an even sprinkling of the dukkah crumb.
Photo Credits: Photography: © Armelle Habib 2024
