Preheat the oven to 425° F, and line a large sheet pan with parchment paper.
Place the sliced tomatoes on a sheet pan lined with a clean kitchen towel and sprinkle with the 2 teaspoons of sea salt. Let stand for 10 minutes for the salt to draw out some of the moisture from the tomatoes.
In a large bowl, mix together the flour, cornmeal, herbs, sea salt, and black pepper.
Add the shredded butter to the flour and mix until it resembles sand.
Pour in the milk and mix just until combined then knead 3-4 times until a shaggy ball of dough forms.
Lightly dust a clean work surface (or directly onto the parchment) with flour and roll the dough into an ⅛” thick circle. Carefully transfer the dough to a parchment paper-lined sheet pan.
Keeping 1 ½” of the edges clear, sprinkle the feta cheese, herbs, and garlic over the dough.
Arrange the tomatoes on top, layering the tomatoes slightly over each other in a circular manner.
Fold in the edges of the dough, and brush the edges with olive oil.