Butternut Squash and Caramelized Onion Galette

Whisk together the flour and salt in a large bowl.

Sprinkle bits of butter over flour and work butter into the flour until mixture resembles coarse meal with pea-sized pieces of butter.

Add sour cream, lemon juice and water and stir with a wooden spoon or spatula until large lumps form.

Tip the mixture onto parchment or plastic wrap and gather into a slightly flattened ball, kneading once or twice to bring it together.

Chill in the fridge until firm, about 1 to 2 hours.

Heat oven to 375°F. Peel squash, halve, scoop out seeds and cut into 1/2-inch dice.

Toss squash with olive oil and a half-teaspoon of the salt and roast on a foil-lined sheet for 30 minutes or until tender, turning midway if needed. Set aside to cool slightly.

While squash roasts, melt butter in a heavy skillet and cook onion over low heat with the remaining 1/2 teaspoon salt and a pinch of sugar, stirring occasionally, until soft and lightly golden brown, about 20 minutes.

Stir in cayenne.

Mix squash, caramelized onions, cheese and herbs together and let cool to room temperature.

Increase oven temperature to 400°F.

On a floured surface, roll the dough into a 12-inch round and transfer to a parchment-lined baking sheet.

Spread the squash, onion, cheese and herb mixture over the dough, leaving a 1 1/2-inch border.

Fold the border over the filling, pleating the edge to make it fit; the center will be open.

Optionally brush the crust with the beaten egg for shine.

Bake until golden brown, 30 to 40 minutes.

Remove from oven, let stand 5 minutes, then slide onto a serving plate and cut into wedges. Serve hot, warm, or at room temperature.