Preheat oven to 400 degrees F. On paper towel-lined plate, arrange tomatoes to draw out moisture.

In large mixing bowl, combine flour and salt. Use pastry cutter to cut butter into flour.

Add chilled water, 1 tablespoon at a time, to thicken dough.

Transfer dough to floured surface. Form into ball (if making single-serving galettes, form into four balls). Using floured rolling pin, roll dough into circle. Transfer to baking sheet.

In center of dough, arrange tomatoes, garlic and caramelized onions. Carefully fold edges up, overlapping lightly as you continue around circle.

Brush crust with olive oil; sprinkle with salt. Bake 25 minutes, until golden.

Top with goat cheese and drizzle of olive oil.