Place all the vegetables in an extra-large bowl. Generously drizzle with oil. Add mustard, Herb de Provence, rosemary and sugar. Season well with salt and pepper. Massage all the veggies with your hands to coat.
Place the veggies onto 2 or 3 large* foil lined baking sheets.
Roast on the middle and top rack of the oven for about 1 to 1½ hours shaking the pan every 30 minutes. Roast until veggies are nicely browned.
CHEF’S TIP *Never overcrowd the veggies. They must only be one layer thick otherwise they will stew and not brown or caramelize. You may need to divide them into 3 or 4 batches depending on how much you are making.