Heat the oven to 425°F (220°C). Arrange two racks in the middle of the oven. Line 2 rimmed baking sheets with parchment paper or aluminum foil.
Scatter the broccoli and cauliflower on one of the rimmed baking sheets. Place the peppers and zucchini on the other.
Pour half of the olive oil over each of the sheets of vegetables. Add to each pan half of the garlic powder, salt, and pepper. Toss to evenly coat, then spread the vegetables in one well-spaced layer on each of the baking sheets.
Roast the vegetables until golden brown, charred on edges, and quite tender, 20 to 25 minutes for the peppers and zucchini and 30 to 35 minutes for the broccoli and cauliflower, tossing the vegetables once or twice during cooking. Check for doneness by poking each vegetable with the tip of a paring knife; they should show very little resistance, like poking a stick of slightly softened butter. If one vegetable is done and the others need more roasting time, remove the fully cooked vegetables to a plate and continue cooking the rest.
When all the vegetables are cooked, squeeze 1/2 of a lemon over each pan of vegetables, toss, taste, and season with salt and pepper, if needed.
Transfer to a serving dish and serve warm or at room temperature.
Very good dish. I have one concern.. I have noticed in may recipes there are vegetable and depending on how many servings you write 0.67 or things like that. 0.67 of what? A cup. of the vegetable itself, of a 5 ounce piece? Would be so much better if in the metric section you would have given us the amount in grams. ( such as 100 gms of …. or 85 grams of something.) our measuring would be more accurate and consistent. I tries 2 servings of this recipe based on what I could understand of some of the mesurements and it was a lot. And some liquids are in gms in the metric side. Very confusing. Sorry, but I feel the measurement entries could be clearer
Made the other night and the kids loved them!