PP here, actually you could probably do this in a frozen pie crust as well, and it would turn out just fine.

This looks pretty straightforward. You could easily buy premade pie crust that you roll out and skip making the crust altogether. You could also probably do this on puff pastry. You can buy it in in sheets in the frozen food section.

http://www.takepart.com/photos/vegetarian-thanksgiving-recipes?cmpid=foodinc-fb#zucchini-and-squash-galette-with-ricotta-cheese-filling

Recipe posted below. This looks really good, but I'm a fairly beginner cook (though getting better!) and taking on much of Thanksgiving by myself. Should I not attempt? Is there a way to do this in a premade crust???

Zucchini And Squash Galette With Ricotta Cheese Filling
Recipe and Photo Courtesy of Thyme by Riley Madel

Ingredients

Crust:

1 1/2 cup unbleached all-purpose flour (I used half whole wheat flour)
1/4 teaspoon salt
8 tablespoons butter, chilled
2 ounces cream cheese, chilled
1/4-1/2 cup of ice water
Filling:

1 medium zucchini
1 medium yellow summer squash
1 clove of garlic
1 cup ricotta cheese
1 tablespoon honey
1 egg white
1 tablespoon fresh thyme
1/2 cup Parmesan
1/4 cup mozzarella
Egg Wash:

1 egg yolk
1 teaspoon water
Topping:

1 tablespoon olive oil
Fresh basil (or whatever fresh herbs you have on hand)
Directions

In a food processor (or a medium bowl) combine flour and salt for crust. Pulse (or cut) in butter. Once butter is mostly into small chunks, pulse (or cut) in cream cheese. Once butter and cream cheese are in pea-size pieces, pulse in 1/4 cup of water until dough begins to come together (adding 1 tablespoon of water extra as needed.) Remove from food processor and shape into a disc (without handling the dough too much.) Wrap in plastic and place in refrigerator.

To make the filling, spread zucchini and squash onto several layers of paper towels, sprinkle with salt, and let drain for 30 minutes. After that time, gently blot the zucchini and squash—set aside. (Snippet's note: For my second galette, I sliced the veggies hours earlier and then put them in the refrigerator. I didn't pat them dry again after taking them out of the refrigerator. This is important to get all of the moisture out because it can make the galette crust soggy as it cooks in the oven.)

For the ricotta mixture, whisk together ricotta, egg white, garlic, honey, thyme, and cheeses—set aside.
Preheat oven to 400?. On a lightly floured surface, roll the pie dough out to a 12-14" circle and transfer to a baking sheet covered in parchment paper (you can also do an ungreased baking sheet but it wasn’t easy to remove the final product).
Spread the ricotta filling evenly over the pie crust, leaving a 2" border around the edge. Next, evenly arrange the zucchini/squash into an overlapping pattern on top of the ricotta filling. Fold over the edges of the crust, pleating as needed to make an even circle.
Combine the egg yolk/water and brush the outer edge of the crust. Drizzle olive oil on top of the zucchini/squash and place in oven.

Bake galette until crust is golden brown and the cheese has puffed, somewhere between 35-45 minutes.
Remove from oven and sprinkle with basil. Cut into wedges and serve. (This is great hot, room temperature, or even straight from the refrigerator as a leftover!)