This tart was a revelation! A happy surprise! It looks so fancy, but really does not require too much work. I can imagine it began its life as a peasant’s winter dinner – a quick pie filled with root vegetables – the only stores that were available with cold snow still covering the ground, and with no sun in sight… but it is a comforting dish, one that suits that season… so strange that I was making it in the heat of summer!
But no matter! What matters is that you make this – and soon! It’s like a Cornish pasty, but meatless, and enough for the whole family (okay, a small family). And if you ignore the price of Gruyere, incredibly inexpensive!
Don’t let the pastry put you off – a real buttery one this, and worth every gram of fat. It comes together easily, and despite the instructions below, won’t falter if it doesn’t get the amount of chill time described.
Potato, Onion, & Gruyere Galette Recipe
Made exactly according to the instructions found here. The only adjustments have been to re-write measurements for southern hemisphere cooks.
Pie/Tart Crust Recipe
*Can be made up to 2 days ahead, cover with plastic wrap, and keep refrigerated.
110g cold unsalted butter, cut into 1/2 inch pieces
3 to 4 tablespoons cold water (I ended up using more; you need just enough water to allow the flour and butter to come together to make a dough)
1 1/4 cup (6 1/4 ounces) plain flour
1/4 teaspoon salt
Whisk flour and salt together in a medium bowl. Add cold, diced butter and quickly break into smaller buttery crumbs between your fingertips (don’t worry if not all the butter is totally broken down – it will make the end result more flaky). Combine quickly with a knife by adding a few tablespoons of iced water. Bring together in your hands, and knead on a floured surface until just smooth.
1 1/4 tablespoon olive oil, plus 1 tbsp for drizzling
2 onions (about 340g), thinly sliced
1/4 tsp finely chopped fresh thyme or rosemary
1/4 tsp plus 1 pinch sea salt
110g Gruyere cheese; coarsely grated
450g red potatoes, washed (left unpeeled) and cut into very thin slices
1 egg, lightly beaten with a teaspoon of water
Preheat oven to 200 degrees Celsius and position an oven rack in the lower third. Line the baking sheet with baking paper. Roll the dough out starting from the centre outward while rotating the dough until the dough is circular and about 32cm in diameter. Transfer to baking sheet and chill for up to1 hour (I didn’t, and it turned out fine).
Heat the 1/2 tbsp olive oil in the medium sauté pan over medium-high heat. Add the onion and cook, stirring occasionally, until soft and lightly colored, about 8 to 10 minutes. Stir in the thyme, 1/4 teaspoon salt, and 5 grinds black pepper and blend well. Transfer to a plate and set aside to cool.
Combine the cooled onion mixture, cheese, and potatoes in a large bowl. Mound the filling in the center of the chilled tart shell, leaving a 3cm border at the edge. Fold that border up around the filling, pleating it to make a pretty enclosure and leaving the center open. Drizzle the filling with the remaining 1 tbsp olive oil and sprinkle lightly with salt and 3 grinds of pepper. Lightly brush the pleated dough with the beaten egg to give it a shine and help it brown in the oven.
Bake the galette for 45 to 50 minutes. (It took my galette only 45 minutes), or until the pastry is golden brown and the potatoes are soft when tested with a paring knife or skewer. Use the metal spatula to life the edge of the galette slightly and check underneath to see if the bottom crust is a beautiful brown color. If so, transfer to a rack to cool for 5 to 10 minutes.
Transfer galette to a serving plate with the cake lifter or 2 spatulas or tart pan bottom supporting the bottom as you move it. Slice with a chef’s knife and serve warm. If you like, serve with dollops of crème fraiche and spoonfuls of caviar a green salad.
Store uncovered at room temperature for up to 6 hours, or cover with plastic wrap and refrigerator for up to 2 days. Reheat in oven at 200 C for 10 to 15 minutes before serving.