Preheat the oven to 375°F (190°C) and carefully unroll the pastry crust into a 9-inch pie dish, crimping the edges.

In a large mixing bowl, whisk together the eggs, heavy cream, salt, and black pepper until completely smooth and blended.

Spread the chopped spinach, crumbled feta cheese, and diced tomatoes evenly across the bottom of the unbaked pastry crust.

Pour the egg mixture slowly over the spinach and feta filling, ensuring it is evenly distributed.

Sprinkle the chopped fresh parsley evenly over the top of the quiche.

Bake for 35 to 45 minutes, or until the center is set and the crust is golden brown. Allow the quiche to cool for 10 to 15 minutes before slicing and serving.