In a small bowl, combine the melted butter, minced garlic, thyme, rosemary, parsley, and lemon zest (if using). Mix well to create the garlic herb butter.
In a large mixing bowl, add the sliced carrots, diced zucchini, chopped bell peppers, and halved Brussels sprouts.
Pour the garlic herb butter over the vegetables and toss to coat evenly. Make sure all the vegetables are well-covered with the butter mixture.
Spread the vegetables in a single layer on a large baking sheet lined with parchment paper.
Season with salt and pepper to taste.
Roast in the preheated oven for 25-30 minutes, or until the vegetables are tender and slightly caramelized, stirring halfway through to ensure even cooking.
Once done, remove from the oven and let cool for a few minutes. Garnish with additional fresh herbs if desired.