• To make the crust: put the flour salt and sugar in a processor and pulse to combine.
• Add the pieces of butter and process until grainy.
• While pulsing, add in the ice water, starting with 1/4 cup, just until the dough holds together when pressed between your fingers.
• Empty the bowl of the processor onto a sheet of plastic wrap and bring it together into a dough.
• Cut the amount in half, shape into disks, and wrap each disk in plastic.
• Refrigerate for 2 hours before rolling out one of the disks for this tart. Line your tart pan with the crust and refrigerate until needed.

to make the tart

• Preheat the oven to 350F. Coat the bottom of a large saute pan with olive oil and cook the onions on medium low until they are soft and caramelized. Rearrange them in the pan occasionally so they cook evenly and try not to let them brown. This can take 1/2 hour or more. Set aside to cool.
• Mix the beaten eggs, milk and cream in a bowl. Add in the herbs, and season with salt and pepper.
• Crumble the goat cheese and spread out evenly on the unbaked crust.
• Top the cheese with the onions and season with a little more salt and pepper.
• Pour the milk mixture into the crust and even out the herbs across the top.
• Bake for about 45 minutes until browned and set.
• Serve warm, cold, or at room temperature.