Italian Harvest Vegetable Soup

2 large carrots , peeled

1 large sweet onion , such as Vidalia

2 tablespoons canola oil (or safflower oil)

4 medium garlic cloves , minced

1/2 red bell pepper , sliced into 1/2-inch strips

1/2 bell pepper , sliced into 1/2-inch strips

6 cups water

1 (28 ounce) can diced tomatoes , undrained

1 cup corn kernel (frozen and thawed, or fresh)

1 cup fennel bulb , chopped (or 1 teaspoon whole fennel seed)

1 teaspoon dried oregano

1/2 teaspoon dried thyme

1/2 teaspoon dried rosemary

4 -5 ounces baby spinach leaves, roughly chopped

1 small zucchini , sliced into 1/2-inch pieces