1. Preheat broiler. Arrange zucchini slices in a single layer on a baking sheet and broil until tops are well charred and slices are slightly wilted, about 10 minutes.
2. Remove from oven and cool for 10 minutes.
3. Place cooled zucchini, peppers, oil, vinegar, parsley, garlic, feta, and black pepper in a food processor and pulse until incorporated but still chunky, 15-20 pulses.
4. Serve spread on toasted baguette slices.