Preheat your oven to 450 degrees Fahrenheit. Line a baking sheet with foil and spray it with nonstick spray.
In a mixing bowl, combine the zucchini, eggplant, grape tomatoes, red onion, and red bell pepper. Drizzle the olive oil over the top and sprinkle with kosher salt, ground black pepper, and dried thyme. Mix well to coat the vegetables.
Spread the vegetable mixture evenly on the baking sheet in a single layer.
Roast the vegetables for about 20 minutes, or until soft and browned.
Once roasted, remove the vegetables and mix in the blue cheese crumbles.
Roll out the pie crust into a circle about 1/8 to 1/4 inch thick and place it on a second baking sheet lined with parchment paper.
Spoon the vegetable and cheese mixture into the center of the pie crust, leaving a 1/2 to 1 inch edge.
Fold the edge of the pie crust over the vegetables, leaving the center exposed.
Bake for another 15 to 20 minutes until the crust is golden.
Let the tart cool slightly before slicing and serving.
