Place all the vegetables, seasonings, oil, and lemon within reach. Keep a large bowl or sheet pan nearby to hold the vegetables after they are prepared.
Rinse the broccoli, carrot, bell pepper, zucchini, and red onion under cool running water. Rub away any visible dirt, then place the vegetables in a colander to drain for 2 minutes.
Spread the vegetables over a clean kitchen towel or several paper towels. Pat them until no visible water remains, paying close attention to the spaces between the broccoli florets.Wet vegetables release steam in the skillet, which can keep their edges from browning. Prepare each vegetable according to the ingredient list:Keep the broccoli and carrots separate from the softer vegetables. Mince the garlic and place it in a small bowl.Cut the broccoli into 1-inch florets.Slice the carrot into 1/4-inch coins.Cut the bell pepper into 1-inch pieces.Slice the zucchini into 1/2-inch half-moons.Cut the red onion into 1/2-inch wedges. Place a dry 12-inch skillet over medium-high heat. Let it preheat for 2 minutes.The skillet should feel hot when you hold your hand about 4 inches above it, but it should not smoke. Pour 2 tablespoons olive oil into the skillet. Tilt the pan to coat the bottom, then heat the oil for 20 to 30 seconds.The oil should look thin and glossy. Remove the pan from the burner for a few seconds if the oil begins to smoke. Add the broccoli and carrots. Spread them into one layer and leave them undisturbed for 2 minutes.Stir and continue cooking for 3 minutes. The broccoli should become bright green with a few browned spots, while the carrots should begin to soften. Add the bell pepper, zucchini, and red onion. Cook for 4 to 5 minutes, stirring every 45 to 60 seconds.Stop cooking when the zucchini is tender around the edges but still holds its shape. The bell pepper should retain a slight bite, and the onion should look glossy. Sprinkle in the kosher salt, black pepper, and dried Italian herbs. Add the minced garlic.Stir and cook for 30 to 45 seconds, until the garlic smells fragrant but has not turned dark brown. Remove the skillet from the heat. Pour 1 tablespoon fresh lemon juice over the vegetables and toss for 15 seconds.Taste one vegetable and add a small pinch of salt or pepper if needed. Transfer the vegetables to a shallow serving bowl. Serve within 5 minutes for the best color and texture.
