Autumn Harvest Minestrone

4 carrots, peeled and chopped into 1-inch pieces

4 small new potatoes, chopped into 1-inch pieces (about 2 cups)

2 leeks, chopped (white and light green parts)

1 medium onion, chopped

2 zucchini, sliced into 1-inch discs

1 14-ounce can diced tomatoes...