2 butternut squash, peeled, seeded, and cut into 2-inch wedges
4 large yellow onions, peeled and each cut into 8 wedges
4 fennel bulbs, stems and tough outer layers removed, each cut into 8 wedges
1 cup olive oil, plus more for greasing the baking sheet
12 cloves garlic, peeled
⅛ teaspoon chili pepper flakes
½ cup fresh thyme leaves
1 tablespoon sea salt
2 teaspoons coarsely ground black pepper
Build a fire in a wood-fired oven or preheat the oven to 450° F.
Char the outer skin of the peppers over the flame of a burner and then place in cold water. Remove the skins, the stems, and the seeds. Quarter the peppers and set aside.
Place the peppers and squash on separate lightly oiled baking sheets. Combine the onion, fennel, and garlic on another lightly oiled baking sheet.
Set aside half the fresh thyme leaves for later use.
Massage each vegetable piece with some of the olive oil and then sprinkle with some chili pepper flakes, some of the remaining fresh thyme, and some of the salt and pepper.
Place the squash in the oven for 5 minutes, turning each piece halfway through. Roast until the cooking side is lightly caramelized.
Place the onions, fennel, and garlic in the oven and cook for 4 minutes, turning each piece halfway through.
Place the peppers in the oven and cook for 3 minutes, turning each piece halfway through.
Check all vegetables for doneness: they should be nicely toasted on the outside and soft but still firm. Remove to a bowl. Toss with the remaining fresh thyme. Adjust seasoning with additional salt and pepper if desired and serve.