In a medium bowl, combine the flour and salt.

Place the chunks of butter on top of the flour in the same bowl.

Place the bowl in the freezer for 1 hour. 

While the flour and butter is in the freezer, whisk together 1/4 cup of the goat cheese, lemon juice and ice water and place in the refrigerator to keep as cold as possible. If you are making the gallette the same day leave the remaining goat cheese out to soften for the filling.

After an hour or more remove the bowl from the freezer.

Using a pastry blender, cut the butter into the flour only blending until you see pea sized chunks of butter.  

Make well in the center of the flour mixture, sprinkle the ice water mixture while fluffing with a fork to combine. Do not over work it. The dough will seem a bit dry and crumbly. 

Turn out onto a work surface and work it into a flat disk, as you work it together you can smear it a bit to get it to come together, but only until it has formed a dough. The key is to still have visible chunks of butter. 

Cover with plastic wrap and refrigerate for 1 hour.

While the dough is chilling: Preheat oven to 375°. 

Toss the butternut squash cubes with olive oil and a half-teaspoon of the salt.

Roast the squash on a foil lined baking sheet for 30-40 minutes or until pieces are tender, tossing and turning the pieces half way through to get them to brown evenly. The cubes of squash should start to brown on the edges and be easily pierced with a fork. Set aside to cool slightly. 

While the squash is roasting, caramelize the onions. Melt butter in a heavy skillet and cook the onion over medium-low heat with the remaining half-teaspoon of salt and pinch of sugar. 

Stirring frequently, cook the onions until soft and lightly golden brown and beginning to caramelize, about 35 – 45 minutes. 

Set aside to cool for a few minutes.

Combine the onions and the butternut squash, stir in the grated cheese, sage, and the cayenne pepper.

Raise the oven temperature to 400°. 

On a floured work surface, roll the dough out into a 12-inch round rough circle. It doesn’t need to be a perfect circle, just try to get it as round as possible. 

Transfer the rolled out pastry to an ungreased baking sheet. 

Spread the remaining goat cheese over the dough leaving a 2 inch boarder. 

Spread squash, onions, cheese and herb mixture over the goat cheese, leaving the 2 inch border. 

Fold the border over the squash, onion and cheese mixture, pleating the edge to make it fit. The center will be open. 

Bake the galette for 35 to 45 minutes or until the pastry is nicely golden brown.

Cut into wedges and serve hot, warm or at room temperature.