For the soup: In a powerful blender, add the carrots, 1 cup of the chicken stock, the creme fraiche, onions, lemon juice, maple syrup, ginger, paprika and nutmeg. Blend until smooth. If needed, add a bit more stock to loosen to the desired texture; this soup should be slightly thick. Taste and season with salt. Blend, taste again and season again if needed. Refrigerate.
For the garnish: In a small dry pan over medium heat, add the pecans, lemon zest and a few grinds of black pepper. Toss and toast until the pecans become fragrant and the lemon zest shines as well.
Pour the chilled soup into bowls and serve topped with the garnish.