Place the carrots in a pot and cover with a generous amount of cold water. Boil until firm-tender. When there, add the broccoli and cauliflower and cook 2 minutes more. Drain well, cool vegetables in iced cold water, and then drain well again. Arrange these vegetables and the bell peppers in a 9-inch x 13-inch casserole. Sprinkle the peas over top. Pour in the stock, drizzle with melted butter and season with salt and pepper. (At this point the casserole could be covered, stored in the fridge and baked later.) Cover and bake in a preheated 350 degrees F oven 20-25 minutes, or until vegetables are heated through. Sprinkle with chopped herb of choice and serve.