The type of food she likes to make, says Danielle Alvarez, head chef of lauded Sydney restaurant Fred’s, is the kind that tastes like home cooking. That’s one of the reason why her food lends itself well to a cookbook such as her recently released Always Add Lemon, of which this recipe comes from.

For this dish, Alvarez was inspired by her friend and fellow top chef Martin Boetz, who co-founded the now-closed but hugely respected Longrain in Sydney before moving out of the city to set up Cooks Co-Op (which gives restaurants access to high-quality ingredients).

“He made a version of this, without tomato, at a lunch we were cooking at,” writes Alvarez. “He told me it was his grandmother’s recipe, and it just has that feel about it – it’s old fashioned and I love it.”

She use both butter and sour cream to make the pastry, which doesn’t require any kneading, just a food processor. “It will be the easiest, most delicious, delicate, flaky, buttery tart you have ever tasted.”

It’s a good option to take to a picnic because it doesn’t need to be eaten warm. She suggested you should serve it with a simple leafy salad.

Tomato, Onion and Cheddar Tart
Serves 6–8
Preparation time: 45 minutes (plus one hour to rest the pastry and more for cooling)
Cooking time: 80 minutes

Ingredients

Pastry
250g plain (all-purpose) flour, plus extra for dusting
150g cold unsalted butter, diced
½ tsp salt
125g sour cream
1 egg

Filling
300g large heirloom tomatoes (approx. 1–2)
400g white onion, thinly sliced
2 tsp chopped thyme
50g unsalted butter
100g sour cream
100g grated cheddar cheese
3 eggs
1 tbsp plain (all-purpose) flour
2 tbsp cream
2 tbsp grated parmesan

Method
Start by making your pastry. In the bowl of a food processor, combine the flour, butter and salt and pulse until the mixture resembles fine crumbs. Add the sour cream and egg and pulse a few more times until the pastry comes together in a ball. Shape this into a disc, wrap in plastic wrap and chill for at least 1 hour in the fridge.

Preheat the oven to 180°C (350°F).

Remove the pastry from the fridge, dust with flour and roll out to a 2–3 mm thickness. Try to keep as round as possible. Gently lift this into the base of a 23–25 cm pie dish or tart tin. You want to leave 1–2 cm of excess pastry hanging over the edge to allow for shrinkage as it bakes.

Use scissors to trim off any wider bits. Press a sheet of baking paper on top of the pastry and fill with baking weights or uncooked rice or beans to prevent the pastry puffing up as it cooks. Place the dish on a tray and bake for 20–30 minutes.

When the crust is looking golden on the edges, remove the baking weights and continue baking for a further 15–20 minutes. If the crust looks like it’s puffing up, poke a few holes in it with a fork to allow steam to escape. When golden all over, remove from the oven and leave to cool completely. This step could be done in advance. Reduce the oven temperature to 160°C (320°F), ready to bake the pie.

Peel your tomatoes by cutting a small X on their base, dropping them into boiling water for 10–20 seconds, then immediately refreshing in iced water. The skin should now peel off easily, starting from the X. Cut into 5 mm (¼ in) slices. Set aside.

In a sauté pan, sauté your onions and thyme in the butter until completely soft and translucent but not coloured. Season with salt and black pepper and set aside to cool. Once cool, mix with the sour cream, cheddar, eggs and flour. Pour the mixture into the base of the tart shell, then layer the sliced tomatoes over the top.

Finally, sprinkle with the cream and parmesan and place on a tray. Bake for 40–60 minutes, or until the tart is no longer wobbly and is completely set. If the crust is browning too much, wrap the edge in foil to allow the custard to continue cooking. Remove from the oven and serve warm or at room temperature with a leafy salad.

This is an edited extract from Always Add Lemon by Danielle Alvarez published by Hardie Grant Books $50.00 and is available where all good books are sold. Photographer: Benito Martin and Jess Johnson. Or buy it here.