First make the crust. In your food processor, add the flour, sugar, and salt. Pulse until combined. Add the cubed butter. Pulse until flour and butter are combined and resembles a sand-like texture. Add the cold water 1 Tbsp at a time and pulse until dough comes together.
Shape dough into a thick disc and wrap tightly with plastic wrap. Place in the freezer for 30 minutes or in the fridge for 1-2 hours.
While dough is chilling, slice tomatoes. Careful not to slice them too thin, you don’t want them to fall apart. Line a baking sheet with paper towels and lay tomato slices on top. Sprinkle with kosher salt all over. Let it sit for 20 minutes to release their juices.
Preheat oven to 400 degrees F. Lay out a large piece of parchment paper on the counter. Take dough out of the freezer and place it on top of the parchment. Roll it out into a large circle about 14 inches in diameter, 1/8 inch thick. The edges don’t have to be perfect.
Spread goat cheese on top of dough leaving about 2 inches all around the edge. Gently pat the tops of the tomatoes to get rid of excess water. Layer tomatoes on top of the goat cheese. You can overlap the tomatoes since they shrink when they bake. Top with salt, pepper, and optional Italian seasoning. Fold the edges of the dough up over the tomatoes, overlapping the dough/pleating it as you go around the galette. Lightly brush some almond milk on top of the outer crust and sprinkle everything bagel seasoning.
Carefully slide parchment paper with galette onto a baking sheet. Bake for 45-50 minutes or until crust is golden brown. Let it rest for 10 minutes, add fresh basil and drizzle balsamic glaze over the top. Slice and serve warm.