This tart is really quite simply to make and will wow your guests. The only stipulation is that you have to use good juicy and ripe tomatoes... mealy tasteless tomatoes won't work at all.
Ingredients for the crust:
2 cup unbleached all purpose flour
1 tbsp sugar
1 tsp salt
8 tbs butter, chopped into small squares
1/3 cup ice water (plus more if needed)
1/2 cup grated Parmesan cheese
Process the flour, sugar and salt in a food processor until combined. Cut the butter into squares and add to the food processor along with the Parmesan cheese and pulse until you have coarse crumbles. Add 4 Tbs of ice water and pulse the mixture until the dough begins to come together, adding more water as needed. It's okay if you have visible pieces of butter throughout the dough, this will yield a flaky crust.
Press the dough into the bottom of a tart pan with a removable bottom. Press the dough up the sides about two-thirds of the way up. Even out the dough well, smoothing over any uneven pieces. Cover with plastic wrap and put it in the fridge for about 45 minutes or until it is firm.
Preheat oven to 350 degrees. Remove the plastic wrap and place the tart pan over a cookie sheet. Cover the crust with foil and place pie weights or dry beans on top of the foil to keep the crust from rising. Bake for 30 minutes and remove from the oven.
For the filling:
1 cup part skim ricotta cheese
1 garlic clove, grated
zest of 1 lemon
1 tbsp. fresh chopped oregano
1 tsbp. fresh chopped parsley
1 tbsp lemon juice
1 tsp. dried oregano
1/3 cup shredded Parmesan
Add the ricotta cheese to the food processor and blend on high speed until you have a much smoother consistency- about 2 minutes. Next grate the garlic clove and add to the food processor along with the lemon juice. Transfer the mixture to a mixing bowl and add the herbs, Parmesan cheese, salt and lemon zest. Once the mixture is blended well, spread this mixture evenly over the tart crust.
For the toppings:
3 large ripe tomatoes
1 tsp. dried oregano
1/4 cup mozzarella cheese
Raise the oven temperature to 425 degrees. Slice the tomatoes into rounds and arrange on top of the ricotta mixture. Slice the onion and arrange on top and in between the tomato slices. Sprinkle the top of the tart with mozzarella cheese and the dried oregano. Transfer to the oven and bake for about 15 minutes. Gently remove the bottom of the pan and transfer the tart to a serving platter.