Make the Parmesan Crust
Place both flours, butter, and Parmesan in a food processor and pulse quickly about 25 times. (You're looking for a sandy textured blend with pea-sized pieces of butter)
Add the ice water and pulse again a few more times (the dough should stick together when you pinch it between two fingers)
Transfer the dough to the tart pan.
Working quickly, distribute the dough by pressing across the bottom, towards the sides, and up to form a rim.
Place in the refrigerator and chill for 15 minutes
Bake the Parmesan Crust
Pull the crust out of the refrigerator and poke each a few times with the tongs of a fork.
Cover the tart with a square of aluminum foil and fill generously with pie weights (or dried beans)
Place it onto a baking sheet and slide the tart onto the middle rack in the oven.
Bake for 15 minutes before pulling the shell out of the oven.
Very gently, peel back and remove the tinfoil containing the pie weights.
Place the uncovered crust back into the oven, weight free, and allow to cook for another 10 minutes, or until it is a deep golden brown in color.
Remove from the oven and sprinkle with a little shredded Parmesan (this will act as another barrier to the tomato filling)
Let cool to room temperature before filling
in a skillet over medium heat, warm the olive oil.
Add the sliced onions and cook, stirring occasionally, until onions are softened and browned about 5 minutes.
Reduce the heat to low, add the smashed garlic, and half of the fresh thyme.
Cook on low, stirring just a few times, for 5-7 minutes, until the garlic is just softened.
Remove from heat.
Slice half of the cherry tomatoes in half. Set aside.
In a medium bowl whisk together eggs, milk, remaining thyme, and a good pinch of sea salt and a grind or two of black pepper.
In a small bowl, stir together ricotta cheese, parsley, and another good pinch of sea salt and a grind of pepper
Finish and Bake the Tomato Pie
In the pre-baked crust, layer the onions and garlic across the bottom.
Add all of the tomatoes, both sliced and whole
Nestle ricotta in four or five dollops across the tart.
Place the tart pan on a rimmed baking sheet.
Carefully pour the egg mixture atop the tomatoes and ricotta and place in the oven.
Bake until egg mixture is firm and not wet, about 40 minutes.
Remove and allow to cool to warm or room temperature.
Serve room temperature or chilled.