01 - Preheat the oven to 425°F (220°C) and line a baking sheet with parchment paper.
02 - Toss the zucchini slices with olive oil, salt, and black pepper. Arrange rounds in a single layer on the prepared baking sheet.
03 - In a mixing bowl, combine breadcrumbs, melted butter, minced garlic, chopped parsley, basil, thyme, Parmesan cheese, lemon zest, and red pepper flakes if using. Mix thoroughly until the mixture is evenly moistened.
04 - Distribute the garlic herb crumble evenly over the zucchini rounds.
05 - Roast in the center of the oven for 25 to 30 minutes, or until the zucchini is fork-tender and the crumble turns golden brown and crisp.
06 - Serve immediately, garnished with extra fresh herbs or a squeeze of lemon juice as desired.