Gather all ingredients before starting recipe.
Pre heat oven to 400°
Slice Kalamata olives and set aside.
Slice tomatoes and place in a colander, season liberally with kosher salt. This will draw out the juices.
Peel and grate one garlic clove into a small bowl with olive oil. Stir to combine.
Combine all cheeses, except goat cheese, in a small bowl, and set aside.
Roll out pastry dough into a 12" circle and slide onto a flat sheet lined with parchment paper.
Brush the dough with a little garlic oil, then spread the goat cheese on the pastry, sprinkle with parmesan and grated mozzarella.
Remove tomato slices from colander and place onto a paper towel. Blot the tops of the tomatoes until they are dry, then lay the tomato slices onto the cheese mixture in concentric circles, starting at the outer edge. Drizzle with the remaining olive oil.
Fold the edges over the galette, pleating them.
Mix one egg yolk and one teaspoon water and brush the wash all over the exposed edge.
Bake for 30-40 minutes in a pre heated 400° oven.
Remove from oven when the crust is golden and sprinkle with fresh thyme.