Heat oil in a 5-quart (4.7 L) Dutch oven or similar size stockpot over low-medium heat. Add garlic cloves and sauté for a minute or two until garlic is softened, but not browned. Remove all of the pieces of garlic; this is very important to keep the recipe low FODMAP. Once all of the garlic pieces are removed add leek and scallion greens and sauté for about 3 minutes or until softened but do not let them brown.

Add broth, potatoes and carrots and bring to a simmer. Cover and simmer for about 10 to 15 minutes or until potatoes and carrots are just tender when pierced with a knife. Add tomatoes, beans, zucchini, corn, fennel, kale and cheese rind and simmer for about 20 to 25 minutes or until vegetables are cooked but still retain some vibrancy of color. Season to taste with salt and pepper, going light on the salt if you plan on using the pesto. Soup is ready to serve. Ladle into bowls and stir about 2 teaspoons of Basil Pesto into each serving, if desired. Soup can be refrigerated in airtight containers for up to 4 days or frozen for 1 month.