01 - Preheat the oven to 225°F. Line two large baking sheets with parchment paper.
02 - Wash and dry the zucchinis. Slice them into very thin rounds (about 1/8 inch thick) using a mandoline or sharp knife for even thickness.
03 - Place zucchini slices on paper towels and gently pat dry to remove excess moisture.
04 - In a large bowl, toss the zucchini slices with olive oil, salt, pepper, and any optional seasonings until evenly coated.
05 - Arrange the slices in a single layer on the prepared baking sheets, ensuring they do not overlap.
06 - Bake for 1 hour. Rotate the trays, then continue baking for an additional 30–45 minutes, or until the chips are crisp and lightly golden.
07 - Remove from the oven and let cool completely on the trays (they will crisp up further as they cool).
08 - Serve immediately, or store in an airtight container for up to 3 days.