Preheat your oven to 375°F (190°C).
Roll out the thawed puff pastry on a lightly floured surface. Carefully place it into your greased 9-inch pie dish, pressing it into the bottom and up the sides. Trim any excess pastry hanging over the edges.
In a skillet, melt a tablespoon of butter over medium heat. Sauté the diced tomatoes and peas for about 5 minutes, just until they soften. Add the sugar to enhance the tomatoes' flavor during the cooking process.
In a mixing bowl, whisk together the eggs and heavy cream until well combined. Stir in the cooked vegetables, chopped artichoke hearts, and half of the shredded Gruyere cheese. Season with salt and pepper to taste.
Pour the vegetable and egg mixture into the prepared puff pastry shell. Top with the remaining Gruyere cheese for a golden, cheesy finish.
Place the quiche in the preheated oven and bake for 35-40 minutes or until the filling is set and the top is lightly golden. A toothpick inserted in the center should come out clean.
Once baked, remove the quiche from the oven and let it cool for about 10 minutes before slicing. This resting period helps the filling set further and makes for easier serving.