Preheat the oven to 400°F (200°C). Toss the zucchini, bell pepper, and cherry tomatoes with olive oil, salt, and pepper. Spread on a baking sheet and roast for 20 minutes.

In a mixing bowl, whisk together the eggs and milk. Stir in the roasted vegetables, spinach, and feta cheese.

Pour the vegetable and egg mixture into the pie crust. Bake for 25-30 minutes or until the quiche is set and lightly golden.

Let the quiche cool for a few minutes before slicing and serving.