This fall soup is full of deep orange carrots and bright red apples, colorful representations of the changing season. Both foods contain cancer-fighting fiber and other potent protective compounds like beta-carotene (carrots) and quercetin (apples). This is a great dish to warm your tummy after a long walk in the cooler weather.
In a Dutch oven or large, heavy pan, heat the canola oil over medium-high heat until hot. Add the onion and leek and sauté for about 4 minutes, until the onion is translucent.
Mix in the carrots and apple. Reduce the heat to medium-low, cover, and cook for 5 minutes, stirring often. Add the broth, cover, and bring to a boil over high heat. Then reduce heat to low and simmer for about 30 minutes, until the carrots are very soft. Remove the pot from the heat and set the soup aside to cool slightly.
In a blender or food processor, puree the soup in batches until smooth. Return soup to pan and heat to very hot before serving. If soup is too thick, add more broth, as desired. Season to taste with salt and pepper and serve, garnishing each serving with mint.