Let’s walk through the process, focusing on the steps for achieving truly crispy chips:

1. Preheat Oven and Prepare Pans: Preheat your oven to a low 250°F (120°C). Line one or two baking sheets with parchment paper. Do not grease the parchment.

2. Slice Zucchini Thinly: Wash and thoroughly dry the zucchinis. Using a mandoline slicer (preferred for consistency) or a very sharp knife, slice the zucchini into very thin rounds, aiming for about 1/8-inch thickness. Consistent thinness is key for even drying and crisping.

3. Remove Excess Moisture (Crucial Step):

• Lay the zucchini slices in a single layer on paper towels. Sprinkle them lightly with salt (this is in addition to the salt in the seasoning mix).
• Allow them to sit for about 10 minutes. You’ll see moisture beading up on the surface as the salt draws it out.
• Gently pat the slices dry with more paper towels, blotting away as much moisture as possible. Don’t skip or rush this step – it’s vital for crispiness!

4. Season the Zucchini Slices:

• Place the dried zucchini slices in a large bowl. Drizzle with 1-2 tablespoons of olive oil and toss gently to coat evenly.
• Add the ½ teaspoon sea salt (or adjust to taste, considering the initial salting), garlic powder, (onion powder, if using), smoked paprika (if using), and black pepper.
• If using Parmesan cheese, add it now. Toss everything again gently to ensure the slices are evenly coated with seasonings and cheese.

5. Arrange and Bake (Low and Slow):

• Arrange the seasoned zucchini slices in a single layer on the parchment-lined baking sheet(s), making sure none overlap. Overlapping traps steam and prevents crisping. Use two sheets if necessary.
• Place the sheets in the preheated oven. Bake for 1.5 to 2 hours (90-120 minutes).
• Flip the slices halfway through the baking time (around the 45-60 minute mark) using tongs or a thin spatula to ensure even crisping on both sides.

6. Check for Crispiness and Cool:

• Start checking around the 90-minute mark. The chips should be shrinking, slightly golden brown (especially around the edges), and feel dry and crispy to the touch. If they still feel soft or flexible, continue baking, checking every 10-15 minutes. Be careful not to let them burn, especially thinner slices or edges.
• Once crispy, remove them from the oven. Let them cool completely on the baking sheet for at least 5-10 minutes. They will crisp up even more as they cool.

Patience during the low, slow bake is essential!