DOUGH
Stir flour and cornmeal together. Cut in butter with your fingertips until butter is in pea-sized lumps.
Stir ice water and sour cream together in a small bowl, then add to flour mixture.
Mix together with a fork until mixture holds together and form into a ball.
Put ball on a piece of plastic wrap, loosely gather plastic wrap around it and twist, then press dough into a disc.
Refrigerate for one hour before rolling out.
Lightly flour a pastry board or clean kitchen counter.
Pat the pastry disc into a flat round. Roll the disc between parchment paper or plastic wrap. It should be slightly larger than the pie plate and 1/8-inch thick.
Remove the plastic wrap on top.
Make sure your tart pan is next to where you are rolling the dough. Carefully lift the
dough up from the bottom wrap and place the dough around the rolling pin, then roll it into your pie plate
FILLING
Preheat oven to 350 F. On a foil lined baking sheet, spread the sliced tomato. Drizzle 1 tablespoon olive oil on top and roast until juicy (about 15 minutes).
Heat the rest of the olive oil in a medium sauté' pan over medium-high heat. Add the shallot, diced potatoes, mushrooms, and sun dried tomatoes. Add the white wine. Season with salt, pepper, and thyme. Cook until soft. (about 10 minutes). Remove from the heat onto a plate and let the filling cool before assembling it in the galette. Set aside about 1/2 cup of the filling with the roasted tomatoes.
If you left the oven on from roasting the tomatoes, great! If you did not, preheat your oven to 350 F.
In a medium sized bowl, whisk together the eggs and cream. Scatter filling ingredients into the galette.
Toss on top the comte’ chunks.
Pour in the egg mixture. Toss on top the reserved vegetable filling and the roasted tomatoes.
Sprinkle a little salt and pepper on top and a bit of the fresh thyme.
Bake for about 40-50 minutes or until the tart is golden brown and the filling is set.
Check tart at about 30 minutes. If the tart shell is browning too much, cover the tart with foil paper for the rest of the baking time. Let tart cool before removing from tart pan or slice directly in the tart pan when warm.