1. Place one rack in the upper third of the oven and the other in the lower third. Heat the oven to 425 degrees .
2. Put the zucchini, red onion, red pepper, eggplant, and garlic on a baking sheet. Combine the olive oil, rosemary, 1/2 teaspoon of the salt, and 1/4 teaspoon of the pepper, drizzle the mixture on the vegetables, and toss them. Roast the vegetables until they have softened and browned around the edges, about 30 minutes. Remove the baking sheet from the oven and let the vegetables cool, about 5 minutes.
3. While the veggies roast, combine the ricotta, goat cheese, feta, egg, green onion, and the remaining salt and pepper in a medium bowl and set aside.
4. Roll out one piece of pastry on a lightly floured surface into a 13-by-11-inch rectangle (cover the other pastry with a clean towel while you're working so that it doesn't dry out). Transfer the pastry to a parchment-lined baking sheet and cut 1-inch strips from all four sides. Create a border around the tart by brushing the edges of the rectangle with water and laying the cut strips on top, trimming to fit. Poke holes in the bottom of the pastry with a fork. Repeat the process to make a second tart crust. Place one baking sheet on the upper rack and one on the lower and bake the pastries for 5 minutes; rotate the pans, swapping the one on the bottom with the one on the top, and bake 5 minutes more. Remove the pastries from the oven, poke them with a fork, and use a spatula to carefully press down the puffed centers. Return the pastries to the oven to cook for 5 minutes more, then cool the pans on wire racks for about 5 minutes.
5. Divide the cheese mixture between the pastries and spread it evenly, then divide and add the vegetables and olives. Bake the tarts until the cheese is set, 15 to 20 minutes, rotating the pans halfway through the cooking time, as in step 4. Cool the tarts on racks for a few minutes, then slice each into six squares and serve warm or at room temperature.